Luo Siyi Rossie, DeMarsh Timothy A, deRiancho Dana, Stelick Alina, Alcaine Samuel D
Department of Food Science, Cornell University, Ithaca, NY 14853, USA.
Foods. 2021 May 27;10(6):1204. doi: 10.3390/foods10061204.
Acid whey is a by-product generated in large quantities during dairy processing, and is characterized by its low pH and high chemical oxygen demand. Due to a lack of reliable disposal pathways, acid whey currently presents a major sustainability challenge to the dairy industry. The study presented in this paper proposes a solution to this issue by transforming yogurt acid whey (YAW) into potentially palatable and marketable beverages through yeast fermentation. In this study, five prototypes were developed and fermented by , , , (strain: Hornindal kveik), and IOC Be Fruits (IOCBF) , respectively. Their fermentation profiles were characterized by changes in density, pH, cell count, and concentrations of ethanol and organic acids. The prototypes were also evaluated on 26 sensory attributes, which were generated through a training session with 14 participants. While (IOCBF) underwent the fastest fermentation (8 days) and the slowest (21 days), and (Hornindal kveik) showed similar fermentation rates, finishing on day 20. The change in pH of the fermentate was similar for all five strains (from around 4.45 to between 4.25 and 4.31). Cell counts remained stable throughout the fermentation for all five strains (at around 6 log colony-forming units (CFU)/mL) except in the case of (Hornindal kveik), which ultimately decreased by 1.63 log CFU/mL. was the only strain unable to utilize all of the sugars in the substrate, with residual galactose remaining after fermentation. While both (IOCBF)- and -fermented samples were characterized by a fruity apple aroma, the former also had an aroma characteristic of lactic acid, dairy products, bakeries and yeast. A chemical odor characteristic of petroleum, gasoline or solvents, was perceived in samples fermented by and . An aroma of poorly aged or rancid cheese or milk also resulted from fermentation. In terms of appearance and mouthfeel, the (IOCBF)-fermented sample was rated the cloudiest, with the heaviest body. This study provides a toolkit for product development in a potential dairy-based category of fermented alcoholic beverages, which can increase revenue for the dairy industry by upcycling the common waste product YAW.
酸性乳清是乳制品加工过程中大量产生的副产品，其特点是pH值低且化学需氧量高。由于缺乏可靠的处置途径，酸性乳清目前给乳制品行业带来了重大的可持续性挑战。本文提出的研究通过酵母发酵将酸奶酸性乳清（YAW）转化为潜在可口且可销售的饮料，从而解决这一问题。在本研究中，分别开发了五种原型产品，并由、、、（菌株：霍宁达尔克维克）和国际奥委会水果（IOCBF）进行发酵。它们的发酵过程通过密度、pH值、细胞计数以及乙醇和有机酸浓度的变化来表征。这些原型产品还根据26种感官属性进行了评估，这些属性是通过对14名参与者进行培训而确定的。虽然（IOCBF）发酵速度最快（8天），发酵速度最慢（21天），但和（霍宁达尔克维克）显示出相似的发酵速度，在第20天完成发酵。所有五种菌株发酵产物的pH值变化相似（从约4.45降至4.25至4.31之间）。除了（霍宁达尔克维克）最终下降了1.63对数CFU/mL外，所有五种菌株在整个发酵过程中细胞计数保持稳定（约为6对数菌落形成单位（CFU）/mL）。是唯一无法利用底物中所有糖分的菌株，发酵后仍有残留半乳糖。虽然（IOCBF）和发酵的样品都具有水果苹果香气，但前者还具有乳酸、乳制品、面包店和酵母的香气特征。在和发酵的样品中察觉到石油、汽油或溶剂的化学气味特征。发酵还产生了陈化不良或酸败的奶酪或牛奶的气味。在外观和口感方面，（IOCBF）发酵的样品被评为最浑浊，质地最浓稠。本研究为潜在的基于乳制品的发酵酒精饮料类别中的产品开发提供了一个工具包，通过将常见的废品YAW升级回收，可以增加乳制品行业的收入。
