The negative effects of proteases produced by psychrotrophic bacteria on dairy products, especially ultra‐high‐temperature (UHT) milk, are gaining attention worldwide. These proteases are especially problematic because it is difficult to control psychrotrophic bacteria during cold storage and to inactivate their heat‐resistant proteases during dairy processing. The predominant psychrotrophic species with spoilage potential in raw milk, Pseudomonas, can produce a thermostable extracellular protease, AprX. A comprehensive understanding of AprX on the aspects of its biological properties, regulation, proteolytic potential, and its impact on UHT milk can contribute to finding approaches to minimize, detect, and inactivate AprX. The progress of current research on AprX is summarized in this review. Reducing the production and activity of AprX has potential for alleviating the problems from the instability of UHT milk during shelf life. Comprehensive Reviews in Food Science and Food Safety, Early View, First published May 10, 2019. Read full journal article here.
Impact of Postharvest Operations on Rice Grain Quality
Postharvest operations, such as drying, storage, and milling, have been used to ameliorate the aging of rice grains and to maintain desirable rice grain quality, and thus play a key role in determining rice commercial value. Rice drying mainly affects milling quality as kernel fissuring that may occur during drying leads to head rice yield reduction. Rice grain aging occurring during storage is inevitable and responsible for the changes in appearance, milling, eating, cooking, and nutritional quality. As milling significantly changes the chemical composition of rice by removing protein‐ and lipid‐rich bran layers, milling can alter the aging process of rice and also affect appearance, eating, and sensory quality, but mainly affects the nutritional quality. Therefore, drying methods, storage conditions, and milling methods warrant further research to achieve desired rice grain quality. This review contributes to better understanding of the impacts of postharvest processes on rice grain quality, and provides insights into potential improvements in these practices for rice production and utilization in the whole rice industry. Comprehensive Reviews in Food Science and Food Safety, Volume 18, Issue 3, May 2019, Pages 626-640. Read full journal article here.
Proper food safety training is essential to decrease incidences and overall rates of foodborne illnesses and outbreaks. Though many commercial restaurants should provide proper food safety training to food handler employees, this training is not always offered or effective. This article summarizes the results of a primary literature study concerning the effectiveness of food safety training in commercial settings. The literature chosen for review contained only studies with experimental food safety training, with before and after training data. Through evaluation of these studies, the best practice for ensuring effective training and follow‐through were the use of food safety training programs, which incorporated both knowledge and behavior‐based training. Journal of Food Science, Early View, First published May 8, 2019. Read full journal article here.
Listeria monocytogenes is a major foodborne pathogen that may contaminate liquid egg yolk (LEY). A background microbiota, purified and identified as Enterococcus faecium with a 99.0% probability, was found in pasteurized unsalted LEY. This study was conducted to investigate the thermal resistance of L. monocytogenes and the background microbiota in unsalted and 10% salted LEY at temperatures between 55 and 67.5°C. Both Weibull model and linear survival model were used to analyze the survival curves. The results of this study may be used to design adequate heating conditions to inactivate L. monocytogenes and E. faecium in LEY. Journal of Food Safety, Early View, First published May 22, 2019. Read full journal article here.