This study demonstrates the valorization of macadamia nutshells,a lignocellulosic agricultural waste,as both a carbon source for amylase production and a support matrix for enzyme immobilization.Under optimized solid-...This study demonstrates the valorization of macadamia nutshells,a lignocellulosic agricultural waste,as both a carbon source for amylase production and a support matrix for enzyme immobilization.Under optimized solid-state fermentation conditions,Aspergillus niger ICP2 synthesized amylase with a peak activity of 0.312 U/mL after 72 hours.A four-step purification process of the crude enzyme extract resulted in a 188.54-fold increase in specific activity,albeit with a final recovery yield of 0.0031%.In parallel,nutshells were carbonized at 600℃,700℃,and 800℃,then chemically activated with ZnCl_(2).The carbon derived at 700℃ exhibited superior physicochemical characteristics,including enhanced porosity and increased availability of functional groups,which enabled effective enzyme adsorption,improved catalytic performance,and enhanced reusability.Immobilized amylase on this support retained approximately 30% of its initial activity after five hydrolysis cycles,demonstrating moderate operational reusability and potential for repeated use in bioprocesses.In contrast,carbon materials from 600℃ and 800℃ showed lower stability and enzyme performance.These findings highlight the critical role of carbonization conditions in designing effective immobilization matrices and underscore the potential of macadamia nutshells as a renewable and sustainable resource for biocatalyst development.This“biowaste-to-biocatalyst”strategy exemplifies a circular bioeconomy model with implications for green chemistry,industrial biocatalysis,and environmental sustainability.展开更多
Vitamin C,a potent antioxidant with broad therapeutic applications,is limited by rapid degradation under environmental stressors,which compromises its stability and bioactivity.This study addresses these limitations b...Vitamin C,a potent antioxidant with broad therapeutic applications,is limited by rapid degradation under environmental stressors,which compromises its stability and bioactivity.This study addresses these limitations by formulating a double nano-emulsion(W/O/W)system incorporating macadamia oil and tea tree oil,using homogenization and phase inversion temperature(PIT)techniques.Comprehensive physicochemical charac-terization,including droplet size,polydispersity index(PDI),zeta potential,turbidity,Fourier transform infrared spectroscopy(FTIR),and SEM,was conducted alongside stability assessments under varying pH,temperature,and storage conditions.The optimized nano-emulsions exhibited nanoscale droplet sizes(10-40 nm),low PDI values(indicating high uniformity),and robust stability.Interestingly,the formulation with 2%W/O loading,with a particle size of 11.57 nm and a PDI of 0.04,demonstrated an antioxidant capacity of 4622.62μg ascorbic acid equivalents(AA)/g,which was significantly higher(p<0.05)compared to both natural oils(macadamia oil:20.91μg AA/g,tea tree oil:16.86μg AA/g)and a 10%Vitamin C aqueous solution(592.94μg AA/g).FTIR analysis confirmed the molecular integrity of Vitamin C and its successful encapsulation with macadamia and tea tree oils,while SEM images revealed uniformly spherical and well-dispersed droplets.Moreover,the formulation retained its structural integrity and antioxidant functionality under diverse pH and thermal conditions.These findings underscore the potential of double nano-emulsion systems to overcome the stability challenges of Vitamin C,offering a promising approach to enhance its bioavailability and therapeutic performance in phar-maceutical and cosmetic applications.展开更多
Macadamia nuts (Macadamia integrifolia) grown in Venezuela have showed an average total fat content of 70%. Oleic acid (18:1) was the main monounsaturated fatty acid (MUFA) (51.3%), followed by palmitoleic acid (16:1,...Macadamia nuts (Macadamia integrifolia) grown in Venezuela have showed an average total fat content of 70%. Oleic acid (18:1) was the main monounsaturated fatty acid (MUFA) (51.3%), followed by palmitoleic acid (16:1, 22.6%). The content of polyunsaturated fatty acids (PUFAs), C18:2 and C18:3 represented 5.4%. Thus, MUFAs and PUFAs together constituted more than 80% of the total fatty acids present. Trans-vaccenic acid was also present (3%). As regards to other phytochemical compounds, tocopherols and tocotrienols were not found in the sample, but the presence of squalene was detected.The antioxidant activity (44.2%) of the extract was produced by the phytochemicals present.展开更多
[Objective] To investigate the annual variation of 9 mineral nutrition ele-ments content in Macadamia integrifolia leaves. [Method] Twenty 6-year-old ＆quot;Guire No. 1＆quot; healthy plants were selected. On the 15th...[Objective] To investigate the annual variation of 9 mineral nutrition ele-ments content in Macadamia integrifolia leaves. [Method] Twenty 6-year-old ＆quot;Guire No. 1＆quot; healthy plants were selected. On the 15th of every month in 2011, 1 leaf in the second round from top-branch in 4 directions of the 20 trees was col ected. The content of 9 mineral elements of N, P, K, Ca, Mg, Zn, Cu, Fe and Mn were deter-mined. [Result] The results showed that the N, P, K content in leaves reached a peak in April, then N content decreased slowly, P content stayed stable, and K con-tent increased slightly; Ca, Fe content decreased in April to different degrees and then increased slowly. Mg content was consistent al year round, meanwhile Mn content decreased slightly. Cu and Zn content reached a peak in April, and then presented a rise-fal trend. [Conclusion] N, K, Ca, Mg should be supplemented in time in practice.展开更多
Macadamia is cultivated for its nutritious edible kernel. In Kenya, the crop is predominantly grown by smallholder farmers mainly for export markets. Macadamia trees also enhance agro-forestry conservation, in the Eas...Macadamia is cultivated for its nutritious edible kernel. In Kenya, the crop is predominantly grown by smallholder farmers mainly for export markets. Macadamia trees also enhance agro-forestry conservation, in the East African farmlands, by providing habitat and floral resources to beneficial arthropods such as insect pollinators. Allogamy of macadamia flowers is largely dependent on insects that pollinate and consequently influence the nut set, retention and yield. However, there is limited information on macadamia insect flower visitors in Kenya. This article assessed the diversity of insects that forage flowers of macadamia crop, and further evaluated their temporal distribution, in Murang’a county, central Kenya. Insect flower visitors were sampled weekly using a butterfly net for twelve consecutive months, from January 2021 to December 2021. Sixty-one insect species were recorded foraging macadamia flowers in Murang’a county, central Kenya. There was a statistical difference in the Simpson diversity index among weather seasons, dry, long rain, cold and short rain (p Apis mellifera), a key pollinator species, being the most abundant flower visitor. This study provides strong baseline information, to scientists and farmers, on probable macadamia pollinator species, in central Kenya. .展开更多
The use of natural fibers as an additive in polymeric matrices has attracted interest of the automotive industries,for its low cost,mechanical properties,biodegradability and lightness.However,the hydrophilic nature o...The use of natural fibers as an additive in polymeric matrices has attracted interest of the automotive industries,for its low cost,mechanical properties,biodegradability and lightness.However,the hydrophilic nature of the fiber makes polymer compatibility difficult.Fiber surface treatments can be used to enhance the fiber/matrix interface.In the present work,polypropylene(PP)composites reinforced with fibers from macadamia nutshell were obtained and characterized.Macadamia nutshell fibers were treated by an alkaline treatment with sodium hydroxide(NaOH 4%)to improve adhesion between fibers and matrix.Fibers were characterized by techniques of Scanning Electron Microscopy(SEM)and X-Ray Diffraction(XRD).The PP was mixed with the macadamia fibers(treated and untreated),in proportions of 5 and 10%(wt/wt)using a thermokinetic mixer.Furthermore tensile,flexural and impact specimens(Pure PP and composites)were prepared by an injection molding process and tested for evaluation of mechanical properties.The results showed that the insertion of treated fibers in the PP matrix increased the stiffness of the composites.However,the composites reinforced with untreated fibers presented higher impact energy absorption when compared to composites reinforced with treated fibers.展开更多
Macadamia,as the main industry of rural revitalization in Guangxi,has high economic value and good ecological benefits.However,the traditional way of drying macadamia nuts after harvest is very extensive.It cannot gua...Macadamia,as the main industry of rural revitalization in Guangxi,has high economic value and good ecological benefits.However,the traditional way of drying macadamia nuts after harvest is very extensive.It cannot guarantee the quality and can cause mildew easily,thereby seriously restricting the industrial development.This paper introduced a device with a weighing device,which allows operators to understand the drying effect in time and thus reduces the loss of nutrition.The device solves the problem of relying on the weather to harvest,and ensures the drying effect of macadamia nuts.展开更多
A greenhouse experiment was conducted at Mahidol University, Thailand from January to May 2009. Macadamia plants were planted in pots with mixed substrate of soil： sand： coconut-coir： rice-husk： charcoal; 3.0： 1....A greenhouse experiment was conducted at Mahidol University, Thailand from January to May 2009. Macadamia plants were planted in pots with mixed substrate of soil： sand： coconut-coir： rice-husk： charcoal; 3.0： 1.0： 0.5： 1.0, respectively. Micro drip-irrigation system was operated 10：00 to 16：00 h daily with a controller scheduled to pump 12 minutes at 12 intervals. The study showed that application of Enshi tablet （18 tablets/plant/year） in a drip-irrigation system enhances growth of Macadamia compared to the application of OsmocoteTM tablet, Modified-enshi and Enshi solution. Significant variation in chlorophyll （a ＋ b） content was observed in Enshi tablet treatment. Soil chemical analyses indicated that the nutrient content in Enshi tablet appeared low compared to other formulations but nutrient removal was considerably brought down by the system, which gives a balance between nutrient removals by crops and addition through fertilizers. Hence, application of Enshi tablet is suggested for Macadamia in a drip-irrigation system.展开更多
In the present context, the objective of this study was to synthesize and analyze the content of AA of macadamia protein and the impact of hydrogen ion concentration (pH) on AA composition. The determination of AA mai...In the present context, the objective of this study was to synthesize and analyze the content of AA of macadamia protein and the impact of hydrogen ion concentration (pH) on AA composition. The determination of AA mainly by cation-exchange chromatography was also investigated. Reproducible and reliable techniques for quantification and identification of AA usually require derivatization. However, techniques such as AA analyzer are composed of cation-exchange chromatography and other components can sideline the derivatization with significant accuracy. The present analysis revealed a higher concentration of essential amino acids especially acidic AA, Glu and Asp and basic AA, Arg than other AA in macadamia protein. The study constitutes first report of use of bubble chart for evaluation of AA and explaination of AAS. The results may elaborate that the degradation of AA of macadamia protein for extraction of pH 11 is caused by the impact of pH. Moreover, the nutritional values of AA present in macadamia protein could change for the better by adjusting pH of extraction.展开更多
In the present work, macadamia protein was enzymatic hydrolyzed to produce peptides which had abundant antioxidant activities. The relative antioxidant capacity was investigated through some in vitro models such as sc...In the present work, macadamia protein was enzymatic hydrolyzed to produce peptides which had abundant antioxidant activities. The relative antioxidant capacity was investigated through some in vitro models such as scavenging activity of DPPH radical, scavenging of ABTS<sup>+</sup> radical and evaluation of the total antioxidant capacity assay. Macadamia protein was characterized by methods of DEAE cellulose cation-exchange chromatography and SDS-PAGE. Besides, method of price graph was used to compare the difference and to investigate the connection between the actual and ideal antioxidant value of the hydrolysates, aiming to reduce this difference.展开更多
The aim of this study was to apply the existing techniques that enable examination ofmacadamia kernels to provide a better understanding of physico-chemical properties of kernels during postharvest processing. These t...The aim of this study was to apply the existing techniques that enable examination ofmacadamia kernels to provide a better understanding of physico-chemical properties of kernels during postharvest processing. These techniques, such as X-ray tomography, could be applied for quality monitoring in the macadamia industry. The objectives of this study were to investigate the browning centre symptoms that usually occur in macadamia nuts-in-shell. The applied techniques included confocal microscopy, X-ray tomography and magnetic resonance imaging （MRI）. Five different varieties of macadamia nuts （A38, 246, 816, 842 and Daddow） were selected to include distinct characteristics, such as drop pattern and growing location. Analysis of the microstructure of kernels by confocal microscopy showed the distribution of possible brown pigment compounds as well as the distribution of lipids, carbohydrates and proteins inside macadamia cells. Physical properties data, including shell density and seed to volume ratio, were obtained by X-ray tomography. Magnetic resonance diffusion tensor imaging used in this study showed marked differences in microstructure which indicate that different varieties exhibit different microstructures expressed as fraction ofanisotropy and apparent diffusion coefficient that appear to be related to the occurrence of the brown centre. Hence, the findings of this study have potential to improve the existing postharvest techniques used in the macadamia processing industry. They will be of benefit to the industry in terms of improved quality control and cost reduction.展开更多
Macadamia has the highest economic value and has always enjoyed the reputation of"king of dried fruits".In the process of digital management,irrigation is the most widely used.This paper designs the automati...Macadamia has the highest economic value and has always enjoyed the reputation of"king of dried fruits".In the process of digital management,irrigation is the most widely used.This paper designs the automatic control drip irrigation device in the digital management of macadamia nuts,including drip irrigation pipe,soil moisture sensor,motor,water storage chamber,water pump and central controller,and then gives an implementation scheme.The device is not only convenient for laying and positioning,but also convenient for controlling the overall irrigation water consumption during each drip irrigation and accurate use and improving the level of digital management.展开更多
The elite Macadamia cultivar,‘Guire 1’,as experimental material,was treated with selenium fertilizer via foliar spraying at various growth stages.The selenium content and free amino acid composition in macadamia nut...The elite Macadamia cultivar,‘Guire 1’,as experimental material,was treated with selenium fertilizer via foliar spraying at various growth stages.The selenium content and free amino acid composition in macadamia nuts of different selenium fertilizer treatments were measured and analyzed.The findings indicated that foliar application of selenium fertilizer effectively enhanced the accumulation of selenium in the kernels of macadamia nuts.The time of foliar application of selenium fertilizer significantly influenced the effective accumulation of selenium in kernels.Notably,foliar application during the full-bloom stage resulted in significantly higher accumulation than that at other stages.Principal component analysis(PCA)was employed to develop a comprehensive evaluation model for the effective accumulation of selenium in kernels from different treatments.The model indicated that the optimal comprehensive quality of free amino acids was attained when the selenium accumulation in kernels reached 0.223 mg/kg.The reliability and validity of the evaluation model were further corroborated through stepwise regression analysis.This study provided theoretical and practical foundations for improving macadamia quality traits and established a basis for standardizing selenium fertilization protocols.展开更多
Green synthesis methods have garnered significant attention as eco-friendly alternatives to conventional chemical approaches,which often involve hazardous substances.In this study,macadamia nut shell extract was used ...Green synthesis methods have garnered significant attention as eco-friendly alternatives to conventional chemical approaches,which often involve hazardous substances.In this study,macadamia nut shell extract was used as a natural stabilizing and capping agent for the sustainable and environmentally friendly synthesis of zinc oxide nanoparticles(ZnO NPs)and copper oxide NPs(CuO NPs).The natural compounds present in the macadamia nut shell extract facilitate the formation of these NPs.The synthesized ZnO and CuO NPs were confirmed by various types of spectroscopic and microscopic techniques.X-ray diffraction(XRD)analysis confirmed that the ZnO NPs exhibited a hexagonal wurtzite structure,whereas the CuO NPs displayed a face-centered cubic lattice structure.The green-synthesized NPs demonstrated excellent antioxidant and antimicrobial properties against both gram-positive and gram-negative bacteria.Moreover,the photocatalytic efficiency of the NPs was assessed by examining the degradation of tetracycline,with ZnO demonstrating superior performance to CuO.The antimicrobial activities of the ZnO and CuO NPs were tested against Staphylococcus aureus(strain 902),Escherichia coli(strain 443),Aspergillus niger,and Candida albicans,and promising results were obtained.Furthermore,both ZnO and CuO NPs exhibited synergistic effects when combined with antibiotics.The newly developed green-synthesized ZnO and CuO NPs are simple,cost effective,environmentally friendly,and utilized for various applications,including food packaging,biosensors,and catalysis in pharmaceutical reactions.展开更多
基金a funded project under the 2024 Hibah Penelitian Produktivitas Guru Besar(Professor Research Productivity Grant)scheme at Jember University.
文摘This study demonstrates the valorization of macadamia nutshells,a lignocellulosic agricultural waste,as both a carbon source for amylase production and a support matrix for enzyme immobilization.Under optimized solid-state fermentation conditions,Aspergillus niger ICP2 synthesized amylase with a peak activity of 0.312 U/mL after 72 hours.A four-step purification process of the crude enzyme extract resulted in a 188.54-fold increase in specific activity,albeit with a final recovery yield of 0.0031%.In parallel,nutshells were carbonized at 600℃,700℃,and 800℃,then chemically activated with ZnCl_(2).The carbon derived at 700℃ exhibited superior physicochemical characteristics,including enhanced porosity and increased availability of functional groups,which enabled effective enzyme adsorption,improved catalytic performance,and enhanced reusability.Immobilized amylase on this support retained approximately 30% of its initial activity after five hydrolysis cycles,demonstrating moderate operational reusability and potential for repeated use in bioprocesses.In contrast,carbon materials from 600℃ and 800℃ showed lower stability and enzyme performance.These findings highlight the critical role of carbonization conditions in designing effective immobilization matrices and underscore the potential of macadamia nutshells as a renewable and sustainable resource for biocatalyst development.This“biowaste-to-biocatalyst”strategy exemplifies a circular bioeconomy model with implications for green chemistry,industrial biocatalysis,and environmental sustainability.
基金Ho Chi Minh City University of Technology(HCMUT),VNU-HCM for supporting this study.
文摘Vitamin C,a potent antioxidant with broad therapeutic applications,is limited by rapid degradation under environmental stressors,which compromises its stability and bioactivity.This study addresses these limitations by formulating a double nano-emulsion(W/O/W)system incorporating macadamia oil and tea tree oil,using homogenization and phase inversion temperature(PIT)techniques.Comprehensive physicochemical charac-terization,including droplet size,polydispersity index(PDI),zeta potential,turbidity,Fourier transform infrared spectroscopy(FTIR),and SEM,was conducted alongside stability assessments under varying pH,temperature,and storage conditions.The optimized nano-emulsions exhibited nanoscale droplet sizes(10-40 nm),low PDI values(indicating high uniformity),and robust stability.Interestingly,the formulation with 2%W/O loading,with a particle size of 11.57 nm and a PDI of 0.04,demonstrated an antioxidant capacity of 4622.62μg ascorbic acid equivalents(AA)/g,which was significantly higher(p<0.05)compared to both natural oils(macadamia oil:20.91μg AA/g,tea tree oil:16.86μg AA/g)and a 10%Vitamin C aqueous solution(592.94μg AA/g).FTIR analysis confirmed the molecular integrity of Vitamin C and its successful encapsulation with macadamia and tea tree oils,while SEM images revealed uniformly spherical and well-dispersed droplets.Moreover,the formulation retained its structural integrity and antioxidant functionality under diverse pH and thermal conditions.These findings underscore the potential of double nano-emulsion systems to overcome the stability challenges of Vitamin C,offering a promising approach to enhance its bioavailability and therapeutic performance in phar-maceutical and cosmetic applications.
文摘Macadamia nuts (Macadamia integrifolia) grown in Venezuela have showed an average total fat content of 70%. Oleic acid (18:1) was the main monounsaturated fatty acid (MUFA) (51.3%), followed by palmitoleic acid (16:1, 22.6%). The content of polyunsaturated fatty acids (PUFAs), C18:2 and C18:3 represented 5.4%. Thus, MUFAs and PUFAs together constituted more than 80% of the total fatty acids present. Trans-vaccenic acid was also present (3%). As regards to other phytochemical compounds, tocopherols and tocotrienols were not found in the sample, but the presence of squalene was detected.The antioxidant activity (44.2%) of the extract was produced by the phytochemicals present.
基金Supported By Guangxi Sci-Tech Achievements International Cooperation Project(1140013-5)Non-profit Basic Research Project of Guangxi Zhuang Autonomous Region(GXNYRKS201406)~~
文摘[Objective] To investigate the annual variation of 9 mineral nutrition ele-ments content in Macadamia integrifolia leaves. [Method] Twenty 6-year-old ＆quot;Guire No. 1＆quot; healthy plants were selected. On the 15th of every month in 2011, 1 leaf in the second round from top-branch in 4 directions of the 20 trees was col ected. The content of 9 mineral elements of N, P, K, Ca, Mg, Zn, Cu, Fe and Mn were deter-mined. [Result] The results showed that the N, P, K content in leaves reached a peak in April, then N content decreased slowly, P content stayed stable, and K con-tent increased slightly; Ca, Fe content decreased in April to different degrees and then increased slowly. Mg content was consistent al year round, meanwhile Mn content decreased slightly. Cu and Zn content reached a peak in April, and then presented a rise-fal trend. [Conclusion] N, K, Ca, Mg should be supplemented in time in practice.
文摘Macadamia is cultivated for its nutritious edible kernel. In Kenya, the crop is predominantly grown by smallholder farmers mainly for export markets. Macadamia trees also enhance agro-forestry conservation, in the East African farmlands, by providing habitat and floral resources to beneficial arthropods such as insect pollinators. Allogamy of macadamia flowers is largely dependent on insects that pollinate and consequently influence the nut set, retention and yield. However, there is limited information on macadamia insect flower visitors in Kenya. This article assessed the diversity of insects that forage flowers of macadamia crop, and further evaluated their temporal distribution, in Murang’a county, central Kenya. Insect flower visitors were sampled weekly using a butterfly net for twelve consecutive months, from January 2021 to December 2021. Sixty-one insect species were recorded foraging macadamia flowers in Murang’a county, central Kenya. There was a statistical difference in the Simpson diversity index among weather seasons, dry, long rain, cold and short rain (p Apis mellifera), a key pollinator species, being the most abundant flower visitor. This study provides strong baseline information, to scientists and farmers, on probable macadamia pollinator species, in central Kenya. .
文摘The use of natural fibers as an additive in polymeric matrices has attracted interest of the automotive industries,for its low cost,mechanical properties,biodegradability and lightness.However,the hydrophilic nature of the fiber makes polymer compatibility difficult.Fiber surface treatments can be used to enhance the fiber/matrix interface.In the present work,polypropylene(PP)composites reinforced with fibers from macadamia nutshell were obtained and characterized.Macadamia nutshell fibers were treated by an alkaline treatment with sodium hydroxide(NaOH 4%)to improve adhesion between fibers and matrix.Fibers were characterized by techniques of Scanning Electron Microscopy(SEM)and X-Ray Diffraction(XRD).The PP was mixed with the macadamia fibers(treated and untreated),in proportions of 5 and 10%(wt/wt)using a thermokinetic mixer.Furthermore tensile,flexural and impact specimens(Pure PP and composites)were prepared by an injection molding process and tested for evaluation of mechanical properties.The results showed that the insertion of treated fibers in the PP matrix increased the stiffness of the composites.However,the composites reinforced with untreated fibers presented higher impact energy absorption when compared to composites reinforced with treated fibers.
基金Supported by Guangxi Science and Technology Program Project of China (Guike AD19245169)Yulin City Scientific Research and Technology Development Plan Project (Yu Shi Ke 20202001,2019Cxpt00A4,Yu Shi Ke 20204038)。
文摘Macadamia,as the main industry of rural revitalization in Guangxi,has high economic value and good ecological benefits.However,the traditional way of drying macadamia nuts after harvest is very extensive.It cannot guarantee the quality and can cause mildew easily,thereby seriously restricting the industrial development.This paper introduced a device with a weighing device,which allows operators to understand the drying effect in time and thus reduces the loss of nutrition.The device solves the problem of relying on the weather to harvest,and ensures the drying effect of macadamia nuts.
文摘A greenhouse experiment was conducted at Mahidol University, Thailand from January to May 2009. Macadamia plants were planted in pots with mixed substrate of soil： sand： coconut-coir： rice-husk： charcoal; 3.0： 1.0： 0.5： 1.0, respectively. Micro drip-irrigation system was operated 10：00 to 16：00 h daily with a controller scheduled to pump 12 minutes at 12 intervals. The study showed that application of Enshi tablet （18 tablets/plant/year） in a drip-irrigation system enhances growth of Macadamia compared to the application of OsmocoteTM tablet, Modified-enshi and Enshi solution. Significant variation in chlorophyll （a ＋ b） content was observed in Enshi tablet treatment. Soil chemical analyses indicated that the nutrient content in Enshi tablet appeared low compared to other formulations but nutrient removal was considerably brought down by the system, which gives a balance between nutrient removals by crops and addition through fertilizers. Hence, application of Enshi tablet is suggested for Macadamia in a drip-irrigation system.
文摘In the present context, the objective of this study was to synthesize and analyze the content of AA of macadamia protein and the impact of hydrogen ion concentration (pH) on AA composition. The determination of AA mainly by cation-exchange chromatography was also investigated. Reproducible and reliable techniques for quantification and identification of AA usually require derivatization. However, techniques such as AA analyzer are composed of cation-exchange chromatography and other components can sideline the derivatization with significant accuracy. The present analysis revealed a higher concentration of essential amino acids especially acidic AA, Glu and Asp and basic AA, Arg than other AA in macadamia protein. The study constitutes first report of use of bubble chart for evaluation of AA and explaination of AAS. The results may elaborate that the degradation of AA of macadamia protein for extraction of pH 11 is caused by the impact of pH. Moreover, the nutritional values of AA present in macadamia protein could change for the better by adjusting pH of extraction.
文摘In the present work, macadamia protein was enzymatic hydrolyzed to produce peptides which had abundant antioxidant activities. The relative antioxidant capacity was investigated through some in vitro models such as scavenging activity of DPPH radical, scavenging of ABTS<sup>+</sup> radical and evaluation of the total antioxidant capacity assay. Macadamia protein was characterized by methods of DEAE cellulose cation-exchange chromatography and SDS-PAGE. Besides, method of price graph was used to compare the difference and to investigate the connection between the actual and ideal antioxidant value of the hydrolysates, aiming to reduce this difference.
文摘The aim of this study was to apply the existing techniques that enable examination ofmacadamia kernels to provide a better understanding of physico-chemical properties of kernels during postharvest processing. These techniques, such as X-ray tomography, could be applied for quality monitoring in the macadamia industry. The objectives of this study were to investigate the browning centre symptoms that usually occur in macadamia nuts-in-shell. The applied techniques included confocal microscopy, X-ray tomography and magnetic resonance imaging （MRI）. Five different varieties of macadamia nuts （A38, 246, 816, 842 and Daddow） were selected to include distinct characteristics, such as drop pattern and growing location. Analysis of the microstructure of kernels by confocal microscopy showed the distribution of possible brown pigment compounds as well as the distribution of lipids, carbohydrates and proteins inside macadamia cells. Physical properties data, including shell density and seed to volume ratio, were obtained by X-ray tomography. Magnetic resonance diffusion tensor imaging used in this study showed marked differences in microstructure which indicate that different varieties exhibit different microstructures expressed as fraction ofanisotropy and apparent diffusion coefficient that appear to be related to the occurrence of the brown centre. Hence, the findings of this study have potential to improve the existing postharvest techniques used in the macadamia processing industry. They will be of benefit to the industry in terms of improved quality control and cost reduction.
基金Supported by Guangxi Science and Technology Program Project of China(Guike AD19245169)Yulin City Scientific Research and Technology Development Plan Project(Yushike 20202001,2019Cxpt00A4,Yushike 20204038).
文摘Macadamia has the highest economic value and has always enjoyed the reputation of"king of dried fruits".In the process of digital management,irrigation is the most widely used.This paper designs the automatic control drip irrigation device in the digital management of macadamia nuts,including drip irrigation pipe,soil moisture sensor,motor,water storage chamber,water pump and central controller,and then gives an implementation scheme.The device is not only convenient for laying and positioning,but also convenient for controlling the overall irrigation water consumption during each drip irrigation and accurate use and improving the level of digital management.
文摘The elite Macadamia cultivar,‘Guire 1’,as experimental material,was treated with selenium fertilizer via foliar spraying at various growth stages.The selenium content and free amino acid composition in macadamia nuts of different selenium fertilizer treatments were measured and analyzed.The findings indicated that foliar application of selenium fertilizer effectively enhanced the accumulation of selenium in the kernels of macadamia nuts.The time of foliar application of selenium fertilizer significantly influenced the effective accumulation of selenium in kernels.Notably,foliar application during the full-bloom stage resulted in significantly higher accumulation than that at other stages.Principal component analysis(PCA)was employed to develop a comprehensive evaluation model for the effective accumulation of selenium in kernels from different treatments.The model indicated that the optimal comprehensive quality of free amino acids was attained when the selenium accumulation in kernels reached 0.223 mg/kg.The reliability and validity of the evaluation model were further corroborated through stepwise regression analysis.This study provided theoretical and practical foundations for improving macadamia quality traits and established a basis for standardizing selenium fertilization protocols.
基金the Faculty of Science and Technology,Thammasat University Fundamental Fund(TU-FF2569/4824641)the Thailand Science Research and Innovation Fundamental Fund.
文摘Green synthesis methods have garnered significant attention as eco-friendly alternatives to conventional chemical approaches,which often involve hazardous substances.In this study,macadamia nut shell extract was used as a natural stabilizing and capping agent for the sustainable and environmentally friendly synthesis of zinc oxide nanoparticles(ZnO NPs)and copper oxide NPs(CuO NPs).The natural compounds present in the macadamia nut shell extract facilitate the formation of these NPs.The synthesized ZnO and CuO NPs were confirmed by various types of spectroscopic and microscopic techniques.X-ray diffraction(XRD)analysis confirmed that the ZnO NPs exhibited a hexagonal wurtzite structure,whereas the CuO NPs displayed a face-centered cubic lattice structure.The green-synthesized NPs demonstrated excellent antioxidant and antimicrobial properties against both gram-positive and gram-negative bacteria.Moreover,the photocatalytic efficiency of the NPs was assessed by examining the degradation of tetracycline,with ZnO demonstrating superior performance to CuO.The antimicrobial activities of the ZnO and CuO NPs were tested against Staphylococcus aureus(strain 902),Escherichia coli(strain 443),Aspergillus niger,and Candida albicans,and promising results were obtained.Furthermore,both ZnO and CuO NPs exhibited synergistic effects when combined with antibiotics.The newly developed green-synthesized ZnO and CuO NPs are simple,cost effective,environmentally friendly,and utilized for various applications,including food packaging,biosensors,and catalysis in pharmaceutical reactions.
