Yaxi Dai

Contamination of fresh blueberries via contact with an equipment surface is an important food hygiene/safety issue. In this study, four and six over-the-row blueberry machine harvesters in Georgia or Oregon were each sampled twice on two different harvest days in the 2022 harvest season. Nine sites on the top loaders (n = 8) and seven sites on the bottom loaders (n = 2) were sampled before and after cleaning/sanitation. Populations of total aerobes (TA), total yeasts and molds (YM), total coliforms (TC), and the presence of fecal coliforms (FC) and enterococci (EC) in collected samples were determined. Data collected was analyzed using the split-plot ANOVA of SAS. On average, cleaned/sanitized surfaces had about one log lower (p ≤ 0.05) TA and YM counts than the uncleaned surfaces, while no difference in TC counts was observed. The vertical and horizontal conveyors and fruit-catch plates had significantly higher TA, YM, and TC counts than other sampled sites. FC and EC were detected in 7.8% or 14.1% of the Georgia samples and 5.6% or 10.2% of the Oregon samples. The type and concentration of sanitizers and frequency and approach of cleaning/sanitation treatments all impacted the hygiene status of berry-contact surfaces of machine harvesters.

Previous work indicated that bran removal promotes network formation in breads prepared from intermediate wheatgrass (IWG) flour. However, refinement reduces yields as well as contents of nutritionally beneficial compounds such as fiber. This study evaluated xylanase pretreatment of IWG bran as a processing option to enhance the properties of bread made with half of the original bran content. Xylanase pretreatment did not affect stickiness but significantly reduced hardness and increased specific loaf volumes compared to negative (without xylanase) and positive controls (with xylanase but without pretreatment). However, the surface of breads with pretreated bran was uneven due to structural collapse during baking. Fewer but larger gas cells were present due to pretreatment. Addition of ascorbic acid modulated these effects, but did not prevent uneven surfaces. Accessible thiol concentrations were slightly but significantly increased by xylanase pretreatment, possibly due to a less compact crumb structure. Endogenous xylanases (apparent activity 0.46 and 5.81 XU/g in flour and bran, respectively) may have been activated during the pretreatment. Moreover, Triticum aestivum xylanase inhibitor activity was also detected (193 and 410 InU/g in flour and bran). Overall, xylanase pretreatment facilitates incorporation of IWG bran into breads, but more research is needed to improve bread appearance.

Numerous dough improvers are used alone or in combination to enhance the quality of baked goods such as breads. While modern consumers demand consistent quality, the expectations for ingredients have changed over the past few years, and reformulations have taken place to provide “clean label” options. However, the effects and mechanisms of blended dough conditioners suitable for such baked products have not been systematically summarized. In this review, dough and bread properties as affected by different improver combinations are examined, with a focus on additive or synergistic interactions between enzymes or between enzymes and ascorbic acid. The combination of enzymes that hydrolyze starch and cell wall polysaccharides has been shown to reduce textural hardness in fresh and stored bakes goods such as breads. Enzymes that hydrolyze arabinoxylans, the main nonstarch polysaccharide in wheat, have synergistic effects with enzymes that result in cross‐linking of wheat flour biopolymers. In some studies, the effects of bread improvers varied for wheat flours of different strength. Overall, bread products in which wheat is used in whole grain form or in a blend with other flours especially benefit from multiple improvers that target different flour constituents in doughs.