In recent years, acid whey production has increased due to a growing demand for Greek yogurt and acidcoagulated cheeses. Acid whey is a dairy by-product for which the industry has long struggled to find a sustainable application. Bulk amounts of acid whey associated with the dairy industry have led to increasing research on ways to valorize it. Industry players are finding ways to use acid whey on-site with ultrafiltration techniques and biodigesters, to reduce transportation costs and provide energy for the facility. Academia has sought to further investigate practical uses and benefits of this by-product. Although modern research has shown many other possible applications for acid whey, no comprehensive review yet exists about its composition, utilization, and health benefits. In this review, the industrial trends, the applications and uses, and the potential health benefits associated with the consumption of acid whey are discussed. The proximal composition of acid whey is discussed in depth. In addition, the potential applications of acid whey, such as its use as a starting material in the production of fermented beverages, as growth medium for cultivation of lactic acid bacteria in replacement of commercial media, and as a substrate for the isolation of lactose and minerals, are reviewed. Finally, the potential health benefits of the major protein constituents of acid whey, bioactive phospholipids, and organic acids such as lactic acid are described. Acid whey has promising applications related to potential health benefits, ranging from antibacterial effects to cognitive development for babies to human gut health.

The mechanisms of bacterial adhesion to human cells involve several complex reactions and activation of genes and proteins. It has been reported that the food components in dairy matrices, such as sugar or salt, can decrease bacterial adhesion to Caco-2 cells. However, it has not been evaluated whether the bacteria grown in media supplemented with milk phospholipids (MPL) can increase or decrease the adhesion of these cells. The objective of this work was to evaluate the effects of MPL on the kinetic growth of lactic acid bacteria (LAB) and their functional characteristics as probiotics, expression of surface protein genes, and adherence to Caco-2 cells. Seven LAB strains isolated from various dairy products were characterized. Five of the tested LAB strains were able to grow in a chemically defined medium supplemented with MPL. Lactobacillus reuteri OSU-PECh-48 showed the highest growth rate and the greatest optical density. All of the strains tested showed tolerance to acidic conditions at pH 3.0 and to bile salts at 0.5 and 1% concentrations. Auto-aggregation and cell surface hydrophobicity ability were evaluated, with nonsignificant differences between the strains grown in MPL and without MPL. Gene expression of 6 surface proteins was evaluated in the presence or absence of MPL. Pediococcus acidilactici OSU-PECh-L and OSU-PECh-48 were the strains with highest relative expression of 5 of the 6 genes evaluated. Lactobacillus paracasei OSU-PECh-BA was the strain with the lowest level of expression of surface protein genes. Most of the bacteria tested had increased adhesion to Caco-2 cells after growth in MPL. The bacteria with the highest degrees of adhesion observed were Lactobacillus paracasei OSU-PECh-3B, Pediococcus acidilactici OSU-PECh-L, and Lactobacillus reuteri OSU-PECh-48. The genes Cnb and EF-Tu increased in expression in the presence of MPL in most of the LAB tested. The results obtained in this work demonstrate the high potential of these LAB strains for use as starters or beneficial cultures in fermentation of not only dairy products but also other food fermentation processes, with promising ability to increase residence time in the gut, modify the microbiome, and improve human health.

The food industry is looking for alternatives to synthetic colorants. Anthocyanins (ACNs) are suitable replacements due to their color characteristics and potential health benefits. The application of sauco (Sambucus peruviana, SP) as a potential source of ACN-based colorants was evaluated and compared to elderberry (Sambucus nigra, SN) and an extract from purple carrots (PC). Color and pigment stability were evaluated using a model beverage system during eight weeks of storage. Copigmentation with chlorogenic acid (CGA) and ferulic acid (FA) were also evaluated. SP ACNs provided darker and more intense colors than those obtained with SN but less intense than those obtained with PC. Addition of CGA and FA resulted in significantly darker colors with higher chroma in beverages colored with SP and SN but not in beverages colored with PC. Copigmentation with FA reduced monomeric pigment half-lives for all ACN sources but increased the chroma half-lives of beverages colored with SP and SN, from 23 to 49 weeks, and from 23 to 55 weeks, respectively. Analyses using liquid chromatography coupled to photodiode array detection and mass spectrometry showed that interaction between non-acylated ACNs and FA resulted in the formation of pyranoanthocyanins. Overall, ACNs from non-acylated sources such as SP, in combination with FA, showed potential for commercial food applications.

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Pyranoanthocyanins are vibrant, naturally derived pigments formed by the reaction of an anthocyanin with a cofactor containing a partially negatively charged carbon. This study compared the thermal stability and degradation products of 10-carboxy-pyranocyanidin-3-glucoside (pyruvic acid cofactor), 10-methyl-pyranocyanidin-3-glucoside (acetone cofactor), and 10-catechyl-pyranocyanidin-3-glucoside (caffeic acid cofactor) with their anthocyanin precursor to evaluate the role of the pyranoanthocyanin C10 substitution on stability. Pyranoanthocyanins exhibited absorbance half-lives ~2.1–8.6 times greater than cyanidin-3-glucoside, with ~15–52% of their original pigment remaining after 12 h of 90 °C heating at pH 3.0. 10-Methyl-pyranocyanidin-3-glucoside was the most stable (p < 0.01) based on UHPLC-PDA analysis, while 10-catechyl-pyranocyanidin-3-glucoside had the most stable color in part due to contribution from a colored degradation compound. Protocatechuic acid formed in all heated samples, which suggested a similar degradation mechanism among pigments. In conclusion, the C10 substitution impacted the extent of pyranoanthocyanin stability and the degradation compounds formed.