Omedi Jacob Ojobi, Huang Jing, Huang Weining, Zheng Jianxian, Zeng Yongqing, Zhang Binle, Zhou Liyuan, Zhao Faqun, Li Ning, Gao Tiecheng
State Key Laboratory of Food Science and Technology, Laboratory of Baking and Fermentation Science, Cereals/Sourdough and Ingredient Functionality Research, Jiangnan University, Wuxi 214122, China.
Fujian Zunjin Health Science and Technology Co., Ltd., IBF International Inc., Quanzhou, Fujian 362200, China.
Heliyon. 2021 Oct 29;7(11):e08290. doi: 10.1016/j.heliyon.2021.e08290. eCollection 2021 Nov.
The objective of this study was to investigate the suitability of incorporating pitaya fruit fermented by antifungal LAB strains and at 1: 30 °C for 24h or 2: 31 °C for 19.5h as an ingredient with respect to bread making performance and bio-preservation effect. Underlying mechanisms related to gluten protein hydrolysis, starch hydrolysis, and yeast activity in dough were explored. The antioxidant activity, antifungal activity and bread making performance of the resulted breads were analyzed. Also, the antifungal phenolic acids in the breads were identified and quantified. Incorporation of fermented substrates in dough increased yeast activity and gas production capacity, but decreased gas retention capacity. This was attributed to increased dough acidity after incorporating fruit substrates. As a result, reducing sugar and free sulfhydryl (SH) groups increased in these doughs which indicated higher starch and gluten protein hydrolysis, respectively. However, SH groups increased at lower rate in presence of substrates fermented by and at condition 2 than 1. This could be due to improvement of gluten network as revealed by decreased α-helix (%) and increased β-turn (%) in secondary gluten structures in these doughs which subsequently resulted in more homogeneous microstructural properties than in presence of unfermented substrate compared to wheat dough. Subsequently, bread specific volume increased (6.6-20.0%) in presence of fermented substrates, especially fermented by at (2). Moreover, bread incorporated with fermented substrates ( than at 1 than 2) had enhanced antioxidant activities, lower fungal growth rates based on challenge tests and mold free shelf life. Antifungal phenolic acids such as gallic acids, caffeic acid, protocatechuic acid were only detected in bread incorporated with fruit substrates, and their total content higher in fermented substrates.
本研究的目的是探讨将经抗真菌乳酸菌菌株在1:30°C发酵24小时或2:31°C发酵19.5小时的火龙果果实作为面包制作原料时的适用性及其生物保鲜效果。探讨了面团中与面筋蛋白水解、淀粉水解和酵母活性相关的潜在机制。分析了所得面包的抗氧化活性、抗真菌活性和面包制作性能。此外，还对面包中的抗真菌酚酸进行了鉴定和定量。在面团中加入发酵底物可提高酵母活性和产气能力，但会降低气体保留能力。这归因于加入水果底物后面团酸度增加。结果，这些面团中的还原糖和游离巯基（SH）基团增加，分别表明淀粉和面筋蛋白水解程度更高。然而，在条件2下由[具体菌株1]和[具体菌株2]发酵的底物存在时，SH基团的增加速率低于条件1。这可能是由于这些面团中次生面筋结构的α-螺旋（%）降低和β-转角（%）增加，表明面筋网络得到改善，与未发酵底物存在时相比，随后导致微观结构性能比小麦面团更均匀。随后，在有发酵底物存在的情况下，面包的比容增加（6.6 - 20.0%），尤其是在（2）条件下由[具体菌株2]发酵的底物。此外，与未发酵底物相比，加入发酵底物（条件2下的[具体菌株2]比条件1下的[具体菌株1]更明显）的面包具有增强的抗氧化活性、基于挑战试验的较低真菌生长速率和无霉菌保质期。仅在加入水果底物的面包中检测到抗真菌酚酸，如没食子酸、咖啡酸、原儿茶酸，且它们在发酵底物中的总含量更高。
