Department of Grain Science and Industry, Kansas State University, Manhattan, KS 66506, USA.
Intralytix, Inc., 8681 Robert Fulton Dr, Columbia, MD 21046, USA.
J Food Prot. 2023 Sep;86(9):100137. doi: 10.1016/j.jfp.2023.100137. Epub 2023 Jul 31.
Contamination of wheat flours with Shiga toxin-producing E. coli (STEC) is a concern for the milling industry. Milling-specific interventions are needed to address this food safety hazard. The objectives for this study were to determine the efficacy of bacteriophage treatment in reducing wheat STEC contamination during tempering, and assess its effects on flour milling and baking quality. Bacteriophage solutions were prepared by mixing sterile water with the bacteriophage treatment at the following levels: 1 × 10 (0.1%), 2.5 × 10 (0.25%), 5 × 10 (0.5%), 1 × 10 (1.0%), and 1 × 10 (10%) PFU/g wheat dosage. Sterile water (0%) was used as the control. Predried wheat grains were inoculated with STEC (O121 and O26) at 5.0 and 6.0 log CFU/g to restore its original moisture content followed by resting for 24 h. Inoculated grains were then tempered (16% moisture, 24 h) using the prepared bacteriophage solutions. Grains were sampled at 0.5, 1, 2, 6, 12, 18, and 24 h during tempering to determine STEC concentration. The effects of the phage solutions on the flour milling and baking quality were also tested. Tempering time, bacteriophage dose, and their interaction had significant effects on phage efficacy (P < 0.05), with better reductions observed at longer tempering times and higher bacteriophage doses. The use of phage solutions reduced (P < 0.05) wheat STEC concentration after tempering, with the 10% treatment (3.2 logs) achieving ahigher reduction than the 1% (2.4 logs) treatment under similar phage preparation. Phage tempering (including at the highest concentration examined, i.e., 10%) produced wheat flours with comparable quality to the control. Phage-treated wheat flour resulted in breads with finer crumb structure, and comparable texture compared to the control. Phage tempering is a viable intervention for wheat milling as it reduced STEC loads of wheat with no detrimental effects to flour milling and baking quality.
小麦面粉中存在产志贺毒素大肠杆菌（STEC）是制粉行业关注的问题。需要采取特定于制粉的干预措施来解决这一食品安全危害。本研究的目的是确定噬菌体处理在调质过程中减少小麦 STEC 污染的效果，并评估其对面粉加工和烘焙质量的影响。噬菌体溶液通过将无菌水与噬菌体处理混合制备，处理水平如下：1×10（0.1%）、2.5×10（0.25%）、5×10（0.5%）、1×10（1.0%）和 1×10（10%）PFU/g 小麦剂量。无菌水（0%）用作对照。将 STEC（O121 和 O26）预干燥的麦粒接种到 5.0 和 6.0 log CFU/g 以恢复其原始水分含量，然后静置 24 h。然后使用制备好的噬菌体溶液对接种的麦粒进行调质（16%水分，24 h）。在调质过程中，每隔 0.5、1、2、6、12、18 和 24 h 采样麦粒以确定 STEC 浓度。还测试了噬菌体溶液对面粉加工和烘焙质量的影响。调质时间、噬菌体剂量及其相互作用对噬菌体效果有显著影响（P<0.05），较长的调质时间和较高的噬菌体剂量可观察到更好的减少效果。噬菌体溶液的使用减少了调质后小麦 STEC 的浓度（P<0.05），与 1%（2.4 对数）处理相比，10%（3.2 对数）处理效果更好。噬菌体调质（包括在检查的最高浓度下）产生的小麦面粉质量与对照面粉相当。噬菌体处理的小麦面粉制成的面包具有更精细的面包屑结构，与对照相比质地相似。噬菌体调质是一种可行的小麦加工干预措施，因为它可以减少小麦中的 STEC 负荷，而对面粉加工和烘焙质量没有不利影响。
