Food Science Research: December/January 2021

Individual Effects of Enzymes and Vital Wheat Gluten on Whole Wheat Bread Properties

The objective of this research was to determine effects of five enzymes on whole wheat bread properties, particularly loaf volume, bread texture, and staling. Enzymes containing conventional α‐amylase (α‐amyl), cellulase (cel), glucose oxidase, maltogenic α‐amylase (m amyl), and xylanase (xyl) were added at three levels. Vital wheat gluten (VWG) was added as an additional, separate treatment at 2.5% (flour weight basis). Enzymes had minimal effect on water absorption and mixing time. Each enzyme increased specific loaf volume for at least one of the usage levels tested. Among the enzyme treatments, the greatest loaf volume was seen for xyl at the medium and high levels. No enzyme was as effective as VWG at increasing loaf volume. Overall, enzymes did not significantly change cell structure. The greatest reduction in fresh bread hardness was obtained for the high level of xyl. VWG, m amyl, and xyl reduced the rate of bread firming over seven days. α‐Amyl, cel, and m amyl decreased starch retrogradation at day 7 as measured by differential scanning calorimetry. M amyl nearly eliminated the endothermic peak for recrystallized amylopectin. This study demonstrated the specific application of enzymes in whole wheat bread to increase loaf volume and decrease initial crumb hardness and bread staling. Journal of Food Safety. Published November 10, 2020. DOI: 10.1111/1750-3841.15517.

Co‐Crystallized Honey with Sucrose: Evaluation of Process and Product Characterization

Honey is a commercial product that presents difficulties in the food industry related to crystallization inside packaging. Dry ingredients are easy to handle. Honey co‐crystallized with sucrose is a dry product that can be used in the food industry as long as it fulfills safety and sensory requirements. The objective of this work was to produce and characterize honey co‐crystallized with sucrose using nine different samples of honey. The process of co‐crystallization of honey (15%) with sucrose resulted in products with water activity from 0.38 to 0.51, moisture values ranging from 1.25% to 2.04% (wet basis), good fluidity (repose angles from 23.40° to 32.28°), and apparent density from 0.46 to 0.55 g/cm3. The products presented morphological structure characteristics of co‐crystallization products. The final products showed good overall sensory acceptance, which opens the possibility of using co‐crystallized honey in food industries. Journal of Food Processing and Preservation. 2020;e14876.

A Rapid Method for Detecting Hygiene Indicators, E. coli, and Coliforms in Dairy Products

This investigation was designed to develop colorimetric tests for rapid detection of Escherichia coli/coliforms. These test(s) for E. coli and coliforms were developed using the modified E. coli selective medium (M‐ECSM) and coliform selective medium, respectively. The selective media contain a combination of group-specific marker enzymes and selective agents. The marker enzymes were screened using chromogenic substrates wherein β‐D‐glucuronidase and glutamate decarboxylase were found specific for E. coli, while β‐D‐galactosidase was found for coliforms. The selectivity of the media was achieved using different concentrations of ampicillin and gentamicin. The optimized test procedures enabled sensitive detection of 0.35 ± 0.10 log cfu/ml of E. coli and 0.57 ± 0.15 log cfu/ml of coliforms at 37°C within 14.30 ± 0.45 and 12.15 ± 0.30 hours, respectively. M‐ECSM selectively inhibited major Enterobacteriaceae contaminants (Salmonella, Shigella, and Yersinia) up to 6 log cfu/ml. Moreover, better selectivity of M‐ECSM was reported against tested commercial chromogenic media. Field evaluation of the developed test(s) reported prevalence of E. coli/coliforms as 57.29/88.54% in 96 raw milk and 16.28/51.16% in 43 pasteurized milk samples. Further, test components were vacuum dried in the form of miniaturized point‐of‐need tests for field application in dairy farms and industries with minimal infrastructural requirements. Journal of Food Safety. 2020;e12839.