In Chihuahua, north Mexico, the berries of Solanum elaeagnifolium (trompillo or silverleaf nightshade) have been used in the manufacture of artisanal filata-type asadero cheese. Solanum elaeagnifolium is a wild plant ...In Chihuahua, north Mexico, the berries of Solanum elaeagnifolium (trompillo or silverleaf nightshade) have been used in the manufacture of artisanal filata-type asadero cheese. Solanum elaeagnifolium is a wild plant that possesses proteases in its fruit;those enzymes exhibit general proteolytic activities, which are useful in traditional asadero cheesemaking as a rennet substitute. These type of cheese is softer than those made with rennin or chymosin due to their water content and proteolysis. Thus, the aim of this work was to explore microbiological susceptibility of asadero cheese made with an extract from ripe berries and compared with those elaborated with commercial rennet. Crude extract of such fruit was obtained by salting out with ammonium sulfate (40%). Cheeses were obtained by a standardized process only changing the enzyme, packaged in plastic bag or vacuum bag and storage at 4℃ -?6℃. The study included the analysis of spoilage bacteria (total aerobic count, yeasts and molds), indicators of hygiene (total coliforms and E. coli) and fecal contamination (fecal coliforms) after 1, 7, 14, 21 and 28 days of production. Although cheese made with S. elaeagnifolium had lower microbial growth, the aerobic count and yeasts and molds count of all cheese samples showing a 28 days shelf life. Total coliforms, in limits beyond the established ones by the Mexican legislation for human consumption with no effect of the enzyme type used for production, as well as for fecal coliforms. Differences were detected just for packaged method, suggesting that good manufacturing practices take place not the plant coagulant.展开更多
The silverleaf whitefly (Bemisia argentifolii Bellows and Perring) is a widely distributed pest of cotton (Gossypium hirsutum L.) and the population levels may be affected by rates of nitrogen fertilization and planti...The silverleaf whitefly (Bemisia argentifolii Bellows and Perring) is a widely distributed pest of cotton (Gossypium hirsutum L.) and the population levels may be affected by rates of nitrogen fertilization and planting date. Field experiments were conducted to investigate the impact of cotton planting date and nitrogen fertilization on silverleaf whitefly population dynamics. Cotton was planted on 26 April and 8 June, for the early and late plantings, respectively. Nitrogen treatments consisted of soil applications of 0, 112, 168 and 224 kg of nitrogen per hectare. The population levels of adult whiteflies were much higher on early-planted cotton than on late planting. Also, increased numbers of adult whiteflies on both early and late plantings occurred with increasing amounts of applied nitrogen.Applied nitrogen increased seed cotton yields of early plantings but had no effect on the yields of late plantings.展开更多
文摘In Chihuahua, north Mexico, the berries of Solanum elaeagnifolium (trompillo or silverleaf nightshade) have been used in the manufacture of artisanal filata-type asadero cheese. Solanum elaeagnifolium is a wild plant that possesses proteases in its fruit;those enzymes exhibit general proteolytic activities, which are useful in traditional asadero cheesemaking as a rennet substitute. These type of cheese is softer than those made with rennin or chymosin due to their water content and proteolysis. Thus, the aim of this work was to explore microbiological susceptibility of asadero cheese made with an extract from ripe berries and compared with those elaborated with commercial rennet. Crude extract of such fruit was obtained by salting out with ammonium sulfate (40%). Cheeses were obtained by a standardized process only changing the enzyme, packaged in plastic bag or vacuum bag and storage at 4℃ -?6℃. The study included the analysis of spoilage bacteria (total aerobic count, yeasts and molds), indicators of hygiene (total coliforms and E. coli) and fecal contamination (fecal coliforms) after 1, 7, 14, 21 and 28 days of production. Although cheese made with S. elaeagnifolium had lower microbial growth, the aerobic count and yeasts and molds count of all cheese samples showing a 28 days shelf life. Total coliforms, in limits beyond the established ones by the Mexican legislation for human consumption with no effect of the enzyme type used for production, as well as for fecal coliforms. Differences were detected just for packaged method, suggesting that good manufacturing practices take place not the plant coagulant.
文摘The silverleaf whitefly (Bemisia argentifolii Bellows and Perring) is a widely distributed pest of cotton (Gossypium hirsutum L.) and the population levels may be affected by rates of nitrogen fertilization and planting date. Field experiments were conducted to investigate the impact of cotton planting date and nitrogen fertilization on silverleaf whitefly population dynamics. Cotton was planted on 26 April and 8 June, for the early and late plantings, respectively. Nitrogen treatments consisted of soil applications of 0, 112, 168 and 224 kg of nitrogen per hectare. The population levels of adult whiteflies were much higher on early-planted cotton than on late planting. Also, increased numbers of adult whiteflies on both early and late plantings occurred with increasing amounts of applied nitrogen.Applied nitrogen increased seed cotton yields of early plantings but had no effect on the yields of late plantings.
