Compared to other melon types, oriental sweet melon （Cucumis melo var. makuwa Makino） is quite a different species with a shorter shelf-life due to its typical climacteric behavior and thin pericarp. The purpose of ...Compared to other melon types, oriental sweet melon （Cucumis melo var. makuwa Makino） is quite a different species with a shorter shelf-life due to its typical climacteric behavior and thin pericarp. The purpose of this experiment is to explore the effects of co- treatment of enhanced freshness formulation （EFF） and 1-methylcyclopropene （1-MCP） on physiological changes and the content of aroma volatile compounds introduced by them of two oriental sweet melon cultivars （Yumeiren and Tianbao） during storage. The melons were stored in incubators with temperature of 15~C and a relative humidity of 85% for 24 d during which fruit quality and related physiological index were measured. Compared to the control, both treatments delayed fruit weight loss rate and kept the fruit firmness, water content and soluble solids content. Ascorbate peroxidase （APX） and phenylalanine ammonia lyase （PAL） activities showed fluctuations in treated melons, while lipoxygenase （LOX） activity （P〈0.01） and malondialdehyde （MDA） content （P〈0.05） decreased compared to control. During the early stage of storage, alcohols and aldehydes were the main volatile compounds, and esters gradually increased during storage. Of all the esters, acetic esters were the main components, followed by oxalic acid esters and other esters. The total content of aroma volatile compounds, esters, alcohols and aldehydes of co-treated melons were all higher than those of 1-MCP treated and control melons. In addition, the aroma volatile peak of co-treated melons occurred later than that of 1-MCP treated and control melons. In summary, co-treatment of EFF and 1-MCP was more beneficial than 1-MCP treatment to delay ripening and senescence, maintain fruit quality, enhance shelf-life and improve levels of aroma volatile compounds.展开更多
In this study,we tested the ability of sodium dehydroacetate(SD)to extend the shelf-life of‘Kyoho’grape.Among the different concentrations of SD tested(0,0.01,0.1 and 1.0 mmol L^(-1)),0.01 mmol L^(-1) SD was the mos...In this study,we tested the ability of sodium dehydroacetate(SD)to extend the shelf-life of‘Kyoho’grape.Among the different concentrations of SD tested(0,0.01,0.1 and 1.0 mmol L^(-1)),0.01 mmol L^(-1) SD was the most effective in prolonging the shelf-life of‘Kyoho’grape.Compared with the control,the weight loss rate,browning index and hydrogen peroxide(H_(2)O_(2))and malonaldehyde contents were significantly lower in the 0.01 mmol L^(-1) SD treatment,whereas the healthy berry rate,berry firmness,total soluble solids(TSS)content,ascorbic acid content and superoxide dismutase(SOD)activity were significantly higher.In addition,an analysis of‘Kyoho’grape DNA using methylation sensitive amplification polymorphism(MSAP)markers showed that the average DNA methylation level was significantly higher in the 0.01 mmol L^(-1) SD treatment than in the control.Together,these results indicate that 0.01 mmol L^(-1) SD could be used to extend the shelf-life of‘Kyoho’grape.Moreover,a strong connection between reactive oxygen species(ROS)metabolism and DNA methylation change during storage was revealed.展开更多
Shelf-life extension of aquatic products is of significant economical importance. To determine the potential effect of chitosan on the shelf-life of filleted tilapia, this study analyzed the bacterial community divers...Shelf-life extension of aquatic products is of significant economical importance. To determine the potential effect of chitosan on the shelf-life of filleted tilapia, this study analyzed the bacterial community diversity in fresh and spoiled tilapia fillets stored at (4 ± 1)℃ and examined the antimicrobial activity of chitosan against relevant bacteria isolates. Results showed that Pseudomonas (20%) and Aeromonas (16%) were abundant in fresh tilapia fillets, whereas Pseudomonas (52%), Aeromonas (32%) and Staphylococcus (12%) were dominant in the spoiled samples. Chitosan showed wide-spectrum antibacterial activity against bacteria isolated from tilapia and 5.0 g L-1 chitosan was selected for application in preservation. We further determined the shelf-life of chitosan-treated, filleted tilapia stored at (4 ± 1)℃ based on microbiological, biochemical and sensory analyses. Results showed that the shelf-life of chitosan-treated, filleted tilapia was extended to 12 d, whereas that of untreated, control samples was 6 d. These indicate that chitosan, as a natural preservative, has great application potential in the shelf-life extension of tilapia fillets.展开更多
The “elimination” of chemical additives used in a wide variety of foods is demanded, while “natural” additives are seen as a benefit for both quality and safety. Researchers are looking for new sources of ingredie...The “elimination” of chemical additives used in a wide variety of foods is demanded, while “natural” additives are seen as a benefit for both quality and safety. Researchers are looking for new sources of ingredients and/or additives. The aim of this work was to study the effect of 1) the addition of 5.00% citrus fibre washing water (CFWW) and 0.02% rosemary essential oil (REO) or 0.02 % thyme essential oil (TEO) and 2) storage conditions on the chemical, microbe- ological and sensorial properties of mortadellas, a bologna-type sausage. CFWW + REO or CFWW + TEO samples stored in vacuum packaging showed the lowest TBA values. The resulting products were packed either in vacuum, modified atmosphere or air pouches and stored for 24 days. Lipid oxidation was assessed by the TBA method, while a quantitative descriptive analysis was carried out for sensory evaluation. Microbiological counts were also determined. CFWW + REO samples stored in vacuum packaging showed the lowest counts of aerobic and lactic acid bacteria. The sensory evaluation provided similar scores for CFWW + REO and CFWW + TEO samples. The lowest scores were obtained for control mortadella stored in air packaging. The addition of citrus fibre washing water and spice essential oils is a technologically viable alternative in emulsified meat products, since they improve customer acceptance and have desirable effects as regards oxidative stability and reduced microbial growth, which contributes to prolonging their shelf-life.展开更多
Uni-modal rainfall pattern has long dry spell wherein sweetpotato is scarce, expensive but cheap at harvest. The crop is mostly consumed, processed or sold. Extending shelf-life of roots is crucial for Malawi and Nort...Uni-modal rainfall pattern has long dry spell wherein sweetpotato is scarce, expensive but cheap at harvest. The crop is mostly consumed, processed or sold. Extending shelf-life of roots is crucial for Malawi and Northern Ghana as the crop has high value. Trials were conducted in the countries at the community level. In the dry season, temperature is cool in Malawi while warm in Ghana, but thru harmattan, the night is cool with low relative humidity. In Malawi, orange-fleshed sweetpotato Zondeni var., white and yellow types were assessed in three types of storage, Afghan ventilated pit store, storage in dry sand of pit-steps, and of a granary In Ghana, local moistened heap and sandbox were compared. In Malawi, weight losses were calculated relative to the quantity stored at start, it was not cumulative. At 1.5 months no significant difference was among treatments. By 3.5 months the pit-steps method emerged to be superior and continued to 6.5 months. Losses in granary were due to shriveling, in the pit-stepsdue to termites and rats, and in ventilated pit due to termites, rats and Java black rot. Sprouting was high in pit-steps, but it was simply removed and roots returned to storage. At 6.5 months, the beta-carotene of Zondeni roots was traceable. Farmers gained high price when selling them as roots were scarce. Women favored the pit-steps because it was manageable. In Ghana, the sandbox was superior to local moistened heap. Methods designed were suitable for home consumption, but will require modification for commercialization.展开更多
The aim of this work was to investigate the fungal population dynamics in ready-to-eat bagged samples of rocket （Diplotaxis spp.）, lettuce baby leaf （Lactuca sativa L.） and ＂songino＂ （Valerianella olitoria L.）...The aim of this work was to investigate the fungal population dynamics in ready-to-eat bagged samples of rocket （Diplotaxis spp.）, lettuce baby leaf （Lactuca sativa L.） and ＂songino＂ （Valerianella olitoria L.） during a shelf-life, in order to evaluate the effects of the storage length and season of production on the spoilage processes. The incidence of toxigenic moulds was particularity studied in order to evaluate a potential production of mycotoxins and allergenic conidia. A total of 900 samples collected from 10 Italian trademarks were analyzed at the 2nd, 5th and 8th day after the packaging in the spring and summer. A very high number of fungi was found and a great variability of moulds and yeasts at the 1 st day of sampling was observed. Regarding to season of production, any seasonal effect on the moulds and yeasts has been observed, but the moulds detected belonged to different species in relation to season. Regarding to storage length, the yeasts and moulds did not showed significant variations during a shelf-life. In relation to vegetable species, the lettuce resulted always less contaminated with respect to other salads, and the rocket presented 1-2 Log cfu/g of increasing in the level of moulds. Regarding to fungi species, the yeasts were significantly predominant respect to moulds. Finally, the toxigenic moulds Aspergillusflavus and Penicillium italicum were found in all the types of salad in the summer, and their growth during the storage at low temperature represented a potential hazard for the mycotoxins and allergenic conidia production in these commodities.展开更多
Animal originated contamination is the main problem of public health and causes human suffering all over the world. Nowadays, radiation technology is used on foods and yielded with positive results. Gamma radiation ca...Animal originated contamination is the main problem of public health and causes human suffering all over the world. Nowadays, radiation technology is used on foods and yielded with positive results. Gamma radiation causes damage in the structure of bacterial DNA and cell walls. This irritation can lead to decrease in bacterial growth such as spoilage and pathogenic organisms （i.e, Salmonella spp., Bacillus cereus, Listeria monocytogenes, Yersinia enterocolitica, Staphylococcus aureus, Escherichia coli O 157：H7） by this means, increased quality and shelf-life can be obtained. However, for the maintaining organoleptic and nutritional quality, it is an obligation to achive the lowest levels of doses according to chemical, physical, microbiological properties of the product. Radiation energy can lead to radiolytic products from lipids, proteins and water which are the maj or components of seafoods. Another problem in seafood industry is quality losses at the retail and distribution. Time-temperature integrations are the major factors affecting the bacterial growth and enzymatic activity on the loss of seafood quality. The purpose of this review is to summarize the available information on the elimination of some food pathogens by irradition, which emphasize the effects of gamma irradiation on the quality and shelf-life of seafoods.展开更多
In this paper a time dependent inventory model is developed on the basis of constant production rate and market demands which are exponentially decreasing. It advances in quest of total average optimum cost considerin...In this paper a time dependent inventory model is developed on the basis of constant production rate and market demands which are exponentially decreasing. It advances in quest of total average optimum cost considering those products which have finite shelf-life. The model also considers the small amount of decay. Without having any sort of backlogs, production starts. Reaching at the desired level of inventories, it stops production. After that due to demands along with the deterioration of the items it initiates its depletion and after certain periods the inventory gets zero. The decay of the products is level dependent. The objective of this paper is to find out the optimum inventory cost and optimum time cycle. The model has also been justified with proving the convex property and by giving a numerical example.展开更多
Banana (Musa spp.) is a highly perishable fruit that requires special handling. In Eritrea, post-harvest handling practices are characterized to be poor and as a result, poor fruit quality and high post-harvest loss a...Banana (Musa spp.) is a highly perishable fruit that requires special handling. In Eritrea, post-harvest handling practices are characterized to be poor and as a result, poor fruit quality and high post-harvest loss are common. Thus, the purpose of this study was to evaluate the effect of different post-harvest handling and ripening methods on quality and shelf-life of banana. A Complete Randomized Design (CRD) was used for evaluating a combination of two levels of post-harvest handling and four ripening methods in a factorial combination conducted in the laboratory of Horticulture at Hamelmalo Agricultural College. Peel colour change, physiological weight loss, pulp to peel ratio, total soluble solids (TSS), pulp pH, ripening period and shelf life were parameters studied. The results showed fruits treated with ripened tomato showed improved characteristics in all parameters compared to those treated with smoke from kerosene burning or mixed with moringa leaf. Similarly, fruits brought directly from the farm were better than those collected from the ripening room after passing the conventional post-harvest handling. Based on the results of this study, it can be concluded that ripening of banana with the help of tomato improves fruit quality and shelf life. Thus, it can be a safe and better alternative to smoking from kerosene burning. While moringa leaf has no potential as an alternative.展开更多
The objective of the present study was to develop models for egg freshness and shelf-life predictions for the selected evaluation indicators including egg weight,Flaugh unit(HU),and albumen height.Experiments were car...The objective of the present study was to develop models for egg freshness and shelf-life predictions for the selected evaluation indicators including egg weight,Flaugh unit(HU),and albumen height.Experiments were carried out at different storage temperatures for a total period of 29-32 d.All data were collected and fitted in to Arrhenius equation for egg freshness,while the HU data were applied to a probability model for shelf-life prediction.The results showed that egg weight,albumen height,and HU decreased significantly,while albumen pH increased with the extension of storage time.The higher the storage temperature,the faster the egg quality decreased.In addition,the bias factor,accuracy factor,and the standard error of prediction were selected to verify the developed quality models.Maximum rescaled R-square statistic,the Hosmer-Lemeshow goodness-of-fit statistic,and the receiver operating characteristic curve were used to evaluate the goodness-of-fit of the developed probability model for the shelf-life of eggs,which indicated that the presented predictive models can be used to assess egg freshness and predict shelf-life during different storage temperatures.展开更多
The aim of this study was to examine the effectiveness of plasma-activated water(PAW)for inactivating Escherichia coli(E.col)and retention of key quality factors for kale.Different plasma discharge times(1,2,3,4,5,and...The aim of this study was to examine the effectiveness of plasma-activated water(PAW)for inactivating Escherichia coli(E.col)and retention of key quality factors for kale.Different plasma discharge times(1,2,3,4,5,and 10 min)and different exposure times(2,4,6,8,10,and 15 min)were used to investigate the inactivation effect of E.coli spot-inoculated on kale.The influence of different exposure times on the pH,hardness and color of kale was studied post-treatment.In addition,the effects of PAW on the shelf-life of kale over 12 d of storage at 4℃ were investigated.The results showed that after the treatment of 5-PAW-8(8 min treatment by PAW generated by 5 min plasma discharge),the population of E.coli on kale was reduced by approximately 1.55 log colony-forming units(CFU)/g and the changes in pH,hardness and color of kale were not significant(P>0.05).During the storage period after 5-PAW-8 treatment,the hardness,weight loss,color,surface morphology and ascorbic acid were found to be better than those of the two control groups(P<0.05).Furthermore,no significant changes were observed in pH values,the content of total phenols,or 1,1-dipheny1-2-picrylhydrazyl radical scavenging capacity(P>0.05).It is indicated that PAW treatment is a promising methodfor improving microbiological safety and extending the shelf-life of kale.展开更多
The effects of rosemary(Rosmarinus officinalis),lemon balm(Melissa officinalis),lavender(Lavandula angustifola),oregano(Origanum vulgare)and savory(Satureja montana)extracts,alone and in mixtures,on lipid oxidation in...The effects of rosemary(Rosmarinus officinalis),lemon balm(Melissa officinalis),lavender(Lavandula angustifola),oregano(Origanum vulgare)and savory(Satureja montana)extracts,alone and in mixtures,on lipid oxidation in cold-marinated shrimp(Parapenaeus longirostris)were studied.During the two-month screening period using the thiobarbituric reactive substances assay(TBARS)the most effective extract mixture(rosemary:oregano:lavender extracts in 3:2:1 ratio,ROL)was selected for the shelf-life study in pilot production of marinated shrimp to determine its effects on the quality characteristics of the final product.Degradation of the omega-3 fatty acids,eicosapentaeonic acid(EPA)and docosahexaenoic acid(DHA)during 8 months of refrigerated storage,was inhibited in shrimp marinated with ROL compared to control samples.In addition,lower levels of total volatile basic nitrogen(TVB-N)and trimethylamine nitrogen(TMA-N)were observed in shrimp treated with extracts while the TBARS values remained below the limit of 3μmol malondialdehyde(MDA)/100g during the 8-month shelf-life study period,whereas the control sample exceeded this value in the third month.The total number of aerobic mesophilic and psychrophilic microorganisms was reduced after marinating with extracts.The obtained results are promising with regard to the application of plant extracts,especially the tested ROL mixture,to extend the shelf-life of food products and to reduce lipid oxidation and microbial load in the food model.展开更多
Due to the complexity of the deterioration process of seafood products,relying on one indicator is not adequate to determine the quality of such products.Usually,shelf-life was estimated based on various indicators co...Due to the complexity of the deterioration process of seafood products,relying on one indicator is not adequate to determine the quality of such products.Usually,shelf-life was estimated based on various indicators complicating the decision-making process.Decision Support Systems are considered as a good solution.The current study aims to establish a simple and novel fuzzy model based on a combination of knowledge-and data-driven approaches to define a fuzzy quality deterioration index(FQDI)in various seafood products(rainbow trout,threadfin bream,and white shrimp samples)during cold storage.Total volatile basic nitrogen(TVB-N)and psychrotrophic microorganisms counts(PMCs)were determined based on traditional methods.The sensory analysis was performed by a data-driven fuzzy approach.Overall,the shelf-life of the rainbow trout fillet was estimated to be 8 d,based on all the freshness parameters.However,the shelf-life of the Japanese threadfin bream fillet was 5-7 d according to the microbial and chemical parameters,respectively.This time for shrimp samples was 6-8 d using sensory score and TVB-N contents.The results of data-driven fuzzy approach showed all of the quality properties were considered as the'Important'-'Very Important'(defuzzification score>75).The TVB-N and PMCs were the most and weakest freshness quality properties(defuzzified-values:84.64 and 78.75,respectively).Based on FQDI,the shelf-life of the rainbow trout,Japanese threadfin bream,and shrimp samples were estimated to be 8,5,and 7 d,respectively.This method was able to successfully provide a comprehensive deterioration index for evaluating the seafood shelf-life.Such a total index can be considered as a comprehensive output(y variable)to predict seafood freshness by rapid and nondestructive method.展开更多
基金financially supported by the Key Project of Liaoning Province(2011215003)the Project of the Science and Technology Bureau of Shenyang,China(F12-277-1-26)
文摘Compared to other melon types, oriental sweet melon （Cucumis melo var. makuwa Makino） is quite a different species with a shorter shelf-life due to its typical climacteric behavior and thin pericarp. The purpose of this experiment is to explore the effects of co- treatment of enhanced freshness formulation （EFF） and 1-methylcyclopropene （1-MCP） on physiological changes and the content of aroma volatile compounds introduced by them of two oriental sweet melon cultivars （Yumeiren and Tianbao） during storage. The melons were stored in incubators with temperature of 15~C and a relative humidity of 85% for 24 d during which fruit quality and related physiological index were measured. Compared to the control, both treatments delayed fruit weight loss rate and kept the fruit firmness, water content and soluble solids content. Ascorbate peroxidase （APX） and phenylalanine ammonia lyase （PAL） activities showed fluctuations in treated melons, while lipoxygenase （LOX） activity （P〈0.01） and malondialdehyde （MDA） content （P〈0.05） decreased compared to control. During the early stage of storage, alcohols and aldehydes were the main volatile compounds, and esters gradually increased during storage. Of all the esters, acetic esters were the main components, followed by oxalic acid esters and other esters. The total content of aroma volatile compounds, esters, alcohols and aldehydes of co-treated melons were all higher than those of 1-MCP treated and control melons. In addition, the aroma volatile peak of co-treated melons occurred later than that of 1-MCP treated and control melons. In summary, co-treatment of EFF and 1-MCP was more beneficial than 1-MCP treatment to delay ripening and senescence, maintain fruit quality, enhance shelf-life and improve levels of aroma volatile compounds.
基金financially supported by the National Natural Science Foundation of China(U1904113)the National Key Research and Development Program of China(2018YFD1000105)+1 种基金the Program for Innovative Research Team(in Science and Technology)in University of Henan Province,China(21IRTSTHN021)the Program for Science&Technology Innovation Talents in Universities of Henan Province,China(21HASTIT035)。
文摘In this study,we tested the ability of sodium dehydroacetate(SD)to extend the shelf-life of‘Kyoho’grape.Among the different concentrations of SD tested(0,0.01,0.1 and 1.0 mmol L^(-1)),0.01 mmol L^(-1) SD was the most effective in prolonging the shelf-life of‘Kyoho’grape.Compared with the control,the weight loss rate,browning index and hydrogen peroxide(H_(2)O_(2))and malonaldehyde contents were significantly lower in the 0.01 mmol L^(-1) SD treatment,whereas the healthy berry rate,berry firmness,total soluble solids(TSS)content,ascorbic acid content and superoxide dismutase(SOD)activity were significantly higher.In addition,an analysis of‘Kyoho’grape DNA using methylation sensitive amplification polymorphism(MSAP)markers showed that the average DNA methylation level was significantly higher in the 0.01 mmol L^(-1) SD treatment than in the control.Together,these results indicate that 0.01 mmol L^(-1) SD could be used to extend the shelf-life of‘Kyoho’grape.Moreover,a strong connection between reactive oxygen species(ROS)metabolism and DNA methylation change during storage was revealed.
基金supported by the Special Funds for the Basic Research and Development Program in the Central Non-profit Research Institutes of China (No.20603022011005)
文摘Shelf-life extension of aquatic products is of significant economical importance. To determine the potential effect of chitosan on the shelf-life of filleted tilapia, this study analyzed the bacterial community diversity in fresh and spoiled tilapia fillets stored at (4 ± 1)℃ and examined the antimicrobial activity of chitosan against relevant bacteria isolates. Results showed that Pseudomonas (20%) and Aeromonas (16%) were abundant in fresh tilapia fillets, whereas Pseudomonas (52%), Aeromonas (32%) and Staphylococcus (12%) were dominant in the spoiled samples. Chitosan showed wide-spectrum antibacterial activity against bacteria isolated from tilapia and 5.0 g L-1 chitosan was selected for application in preservation. We further determined the shelf-life of chitosan-treated, filleted tilapia stored at (4 ± 1)℃ based on microbiological, biochemical and sensory analyses. Results showed that the shelf-life of chitosan-treated, filleted tilapia was extended to 12 d, whereas that of untreated, control samples was 6 d. These indicate that chitosan, as a natural preservative, has great application potential in the shelf-life extension of tilapia fillets.
文摘The “elimination” of chemical additives used in a wide variety of foods is demanded, while “natural” additives are seen as a benefit for both quality and safety. Researchers are looking for new sources of ingredients and/or additives. The aim of this work was to study the effect of 1) the addition of 5.00% citrus fibre washing water (CFWW) and 0.02% rosemary essential oil (REO) or 0.02 % thyme essential oil (TEO) and 2) storage conditions on the chemical, microbe- ological and sensorial properties of mortadellas, a bologna-type sausage. CFWW + REO or CFWW + TEO samples stored in vacuum packaging showed the lowest TBA values. The resulting products were packed either in vacuum, modified atmosphere or air pouches and stored for 24 days. Lipid oxidation was assessed by the TBA method, while a quantitative descriptive analysis was carried out for sensory evaluation. Microbiological counts were also determined. CFWW + REO samples stored in vacuum packaging showed the lowest counts of aerobic and lactic acid bacteria. The sensory evaluation provided similar scores for CFWW + REO and CFWW + TEO samples. The lowest scores were obtained for control mortadella stored in air packaging. The addition of citrus fibre washing water and spice essential oils is a technologically viable alternative in emulsified meat products, since they improve customer acceptance and have desirable effects as regards oxidative stability and reduced microbial growth, which contributes to prolonging their shelf-life.
文摘Uni-modal rainfall pattern has long dry spell wherein sweetpotato is scarce, expensive but cheap at harvest. The crop is mostly consumed, processed or sold. Extending shelf-life of roots is crucial for Malawi and Northern Ghana as the crop has high value. Trials were conducted in the countries at the community level. In the dry season, temperature is cool in Malawi while warm in Ghana, but thru harmattan, the night is cool with low relative humidity. In Malawi, orange-fleshed sweetpotato Zondeni var., white and yellow types were assessed in three types of storage, Afghan ventilated pit store, storage in dry sand of pit-steps, and of a granary In Ghana, local moistened heap and sandbox were compared. In Malawi, weight losses were calculated relative to the quantity stored at start, it was not cumulative. At 1.5 months no significant difference was among treatments. By 3.5 months the pit-steps method emerged to be superior and continued to 6.5 months. Losses in granary were due to shriveling, in the pit-stepsdue to termites and rats, and in ventilated pit due to termites, rats and Java black rot. Sprouting was high in pit-steps, but it was simply removed and roots returned to storage. At 6.5 months, the beta-carotene of Zondeni roots was traceable. Farmers gained high price when selling them as roots were scarce. Women favored the pit-steps because it was manageable. In Ghana, the sandbox was superior to local moistened heap. Methods designed were suitable for home consumption, but will require modification for commercialization.
文摘The aim of this work was to investigate the fungal population dynamics in ready-to-eat bagged samples of rocket （Diplotaxis spp.）, lettuce baby leaf （Lactuca sativa L.） and ＂songino＂ （Valerianella olitoria L.） during a shelf-life, in order to evaluate the effects of the storage length and season of production on the spoilage processes. The incidence of toxigenic moulds was particularity studied in order to evaluate a potential production of mycotoxins and allergenic conidia. A total of 900 samples collected from 10 Italian trademarks were analyzed at the 2nd, 5th and 8th day after the packaging in the spring and summer. A very high number of fungi was found and a great variability of moulds and yeasts at the 1 st day of sampling was observed. Regarding to season of production, any seasonal effect on the moulds and yeasts has been observed, but the moulds detected belonged to different species in relation to season. Regarding to storage length, the yeasts and moulds did not showed significant variations during a shelf-life. In relation to vegetable species, the lettuce resulted always less contaminated with respect to other salads, and the rocket presented 1-2 Log cfu/g of increasing in the level of moulds. Regarding to fungi species, the yeasts were significantly predominant respect to moulds. Finally, the toxigenic moulds Aspergillusflavus and Penicillium italicum were found in all the types of salad in the summer, and their growth during the storage at low temperature represented a potential hazard for the mycotoxins and allergenic conidia production in these commodities.
文摘Animal originated contamination is the main problem of public health and causes human suffering all over the world. Nowadays, radiation technology is used on foods and yielded with positive results. Gamma radiation causes damage in the structure of bacterial DNA and cell walls. This irritation can lead to decrease in bacterial growth such as spoilage and pathogenic organisms （i.e, Salmonella spp., Bacillus cereus, Listeria monocytogenes, Yersinia enterocolitica, Staphylococcus aureus, Escherichia coli O 157：H7） by this means, increased quality and shelf-life can be obtained. However, for the maintaining organoleptic and nutritional quality, it is an obligation to achive the lowest levels of doses according to chemical, physical, microbiological properties of the product. Radiation energy can lead to radiolytic products from lipids, proteins and water which are the maj or components of seafoods. Another problem in seafood industry is quality losses at the retail and distribution. Time-temperature integrations are the major factors affecting the bacterial growth and enzymatic activity on the loss of seafood quality. The purpose of this review is to summarize the available information on the elimination of some food pathogens by irradition, which emphasize the effects of gamma irradiation on the quality and shelf-life of seafoods.
文摘In this paper a time dependent inventory model is developed on the basis of constant production rate and market demands which are exponentially decreasing. It advances in quest of total average optimum cost considering those products which have finite shelf-life. The model also considers the small amount of decay. Without having any sort of backlogs, production starts. Reaching at the desired level of inventories, it stops production. After that due to demands along with the deterioration of the items it initiates its depletion and after certain periods the inventory gets zero. The decay of the products is level dependent. The objective of this paper is to find out the optimum inventory cost and optimum time cycle. The model has also been justified with proving the convex property and by giving a numerical example.
文摘Banana (Musa spp.) is a highly perishable fruit that requires special handling. In Eritrea, post-harvest handling practices are characterized to be poor and as a result, poor fruit quality and high post-harvest loss are common. Thus, the purpose of this study was to evaluate the effect of different post-harvest handling and ripening methods on quality and shelf-life of banana. A Complete Randomized Design (CRD) was used for evaluating a combination of two levels of post-harvest handling and four ripening methods in a factorial combination conducted in the laboratory of Horticulture at Hamelmalo Agricultural College. Peel colour change, physiological weight loss, pulp to peel ratio, total soluble solids (TSS), pulp pH, ripening period and shelf life were parameters studied. The results showed fruits treated with ripened tomato showed improved characteristics in all parameters compared to those treated with smoke from kerosene burning or mixed with moringa leaf. Similarly, fruits brought directly from the farm were better than those collected from the ripening room after passing the conventional post-harvest handling. Based on the results of this study, it can be concluded that ripening of banana with the help of tomato improves fruit quality and shelf life. Thus, it can be a safe and better alternative to smoking from kerosene burning. While moringa leaf has no potential as an alternative.
基金supported by the Key Research and Development Program of Shandong Province(No.2019GNC106024)the Shandong Poultry Industry Innovation Team Construction Project(SDAIT-11-14)the High-level Talent Research Fund of Qingdao Agricultural University(No.6631120080/1111317),China.
文摘The objective of the present study was to develop models for egg freshness and shelf-life predictions for the selected evaluation indicators including egg weight,Flaugh unit(HU),and albumen height.Experiments were carried out at different storage temperatures for a total period of 29-32 d.All data were collected and fitted in to Arrhenius equation for egg freshness,while the HU data were applied to a probability model for shelf-life prediction.The results showed that egg weight,albumen height,and HU decreased significantly,while albumen pH increased with the extension of storage time.The higher the storage temperature,the faster the egg quality decreased.In addition,the bias factor,accuracy factor,and the standard error of prediction were selected to verify the developed quality models.Maximum rescaled R-square statistic,the Hosmer-Lemeshow goodness-of-fit statistic,and the receiver operating characteristic curve were used to evaluate the goodness-of-fit of the developed probability model for the shelf-life of eggs,which indicated that the presented predictive models can be used to assess egg freshness and predict shelf-life during different storage temperatures.
基金supported by the Grants from the China NationalCenterfor Food Safety Risk Assessment (No.20210349-6602421216)the Qingdao Science and Technology Demonstration and Guidance Project (No.21-1-4-ny-17-nsh)the High-level Talent Research Fund of Qingdao Agricultural University (No.6631115043),China。
文摘The aim of this study was to examine the effectiveness of plasma-activated water(PAW)for inactivating Escherichia coli(E.col)and retention of key quality factors for kale.Different plasma discharge times(1,2,3,4,5,and 10 min)and different exposure times(2,4,6,8,10,and 15 min)were used to investigate the inactivation effect of E.coli spot-inoculated on kale.The influence of different exposure times on the pH,hardness and color of kale was studied post-treatment.In addition,the effects of PAW on the shelf-life of kale over 12 d of storage at 4℃ were investigated.The results showed that after the treatment of 5-PAW-8(8 min treatment by PAW generated by 5 min plasma discharge),the population of E.coli on kale was reduced by approximately 1.55 log colony-forming units(CFU)/g and the changes in pH,hardness and color of kale were not significant(P>0.05).During the storage period after 5-PAW-8 treatment,the hardness,weight loss,color,surface morphology and ascorbic acid were found to be better than those of the two control groups(P<0.05).Furthermore,no significant changes were observed in pH values,the content of total phenols,or 1,1-dipheny1-2-picrylhydrazyl radical scavenging capacity(P>0.05).It is indicated that PAW treatment is a promising methodfor improving microbiological safety and extending the shelf-life of kale.
基金supported by the Croatian Science Foundation under the project IP-2014-09-6897Croatian Agency for SMEs,Innovation and Investments HAMAG-BICRO under Proof of Concept Program,project Improvement of technological process for marinating prawns(PoC7_6_09).
文摘The effects of rosemary(Rosmarinus officinalis),lemon balm(Melissa officinalis),lavender(Lavandula angustifola),oregano(Origanum vulgare)and savory(Satureja montana)extracts,alone and in mixtures,on lipid oxidation in cold-marinated shrimp(Parapenaeus longirostris)were studied.During the two-month screening period using the thiobarbituric reactive substances assay(TBARS)the most effective extract mixture(rosemary:oregano:lavender extracts in 3:2:1 ratio,ROL)was selected for the shelf-life study in pilot production of marinated shrimp to determine its effects on the quality characteristics of the final product.Degradation of the omega-3 fatty acids,eicosapentaeonic acid(EPA)and docosahexaenoic acid(DHA)during 8 months of refrigerated storage,was inhibited in shrimp marinated with ROL compared to control samples.In addition,lower levels of total volatile basic nitrogen(TVB-N)and trimethylamine nitrogen(TMA-N)were observed in shrimp treated with extracts while the TBARS values remained below the limit of 3μmol malondialdehyde(MDA)/100g during the 8-month shelf-life study period,whereas the control sample exceeded this value in the third month.The total number of aerobic mesophilic and psychrophilic microorganisms was reduced after marinating with extracts.The obtained results are promising with regard to the application of plant extracts,especially the tested ROL mixture,to extend the shelf-life of food products and to reduce lipid oxidation and microbial load in the food model.
基金financially supported by the Iran National Science Foundation(No.98013631).
文摘Due to the complexity of the deterioration process of seafood products,relying on one indicator is not adequate to determine the quality of such products.Usually,shelf-life was estimated based on various indicators complicating the decision-making process.Decision Support Systems are considered as a good solution.The current study aims to establish a simple and novel fuzzy model based on a combination of knowledge-and data-driven approaches to define a fuzzy quality deterioration index(FQDI)in various seafood products(rainbow trout,threadfin bream,and white shrimp samples)during cold storage.Total volatile basic nitrogen(TVB-N)and psychrotrophic microorganisms counts(PMCs)were determined based on traditional methods.The sensory analysis was performed by a data-driven fuzzy approach.Overall,the shelf-life of the rainbow trout fillet was estimated to be 8 d,based on all the freshness parameters.However,the shelf-life of the Japanese threadfin bream fillet was 5-7 d according to the microbial and chemical parameters,respectively.This time for shrimp samples was 6-8 d using sensory score and TVB-N contents.The results of data-driven fuzzy approach showed all of the quality properties were considered as the'Important'-'Very Important'(defuzzification score>75).The TVB-N and PMCs were the most and weakest freshness quality properties(defuzzified-values:84.64 and 78.75,respectively).Based on FQDI,the shelf-life of the rainbow trout,Japanese threadfin bream,and shrimp samples were estimated to be 8,5,and 7 d,respectively.This method was able to successfully provide a comprehensive deterioration index for evaluating the seafood shelf-life.Such a total index can be considered as a comprehensive output(y variable)to predict seafood freshness by rapid and nondestructive method.
