Sustainable production of functional protein hydrolysates from dairy and poultry byproducts: A Biotechnological approach

The dairy and poultry industries, due to their high processing volumes, produce waste streams with significant environmental implications, threatening ecosystems. Valorizing these waste streams by recovering crucial nutrients, such as proteins, offers a sustainable solution to meet the needs of a growing human population. However, the extraction of proteins or protein-derived ingredients, like peptides, from these byproducts poses challenges, necessitating innovative biotechnological approaches (Seberini, 2020; Semeria et al., 2020; Zhengxia et al., 2018).

The objective of this research is to valorize acid whey and mechanically separated turkey (MST) through a combined fermentation. These byproducts, rich in proteins and carbohydrates, offer potential for sustainable valorization. A series of fermentation treatments were conducted using different combinations of Acid Whey, MST, Molasses and Lactobacillus rhamnosus (OSU-PECh-69). The experimental design was a completely randomized design with five treatments and three controls.  Each treatment was performed in triplicate. Data were analyzed using ANOVA and Tukey's HSD post-hoc test. The fermentation process generated protein hydrolysates with improved functionalities and bioactivities.

Results from fermentation treatments employing Lactobacillus rhamnosus (OSU-PECh-69) or natural microbiota provided insights into hydrolysis yields, peptide characteristics, and molecular weight distribution. Dynamic changes in pH, soluble protein content, and molecular weight over the 10-day fermentation period signify the transformative nature of the process. The analysis of the antioxidant activity, using DPPH and ABTS assays, revealed that the treatments inoculated exhibited enhanced antioxidant activity with the highest scavenger activity at 46.15 % ±0.01 and 89.26% ±0.04 of inhibition respectively. Lytic activity against Gram-positive bacteria was observed across all treatments, in the supernatant and pellet fractions. Growth inhibition of the fermentates was also present in all the treatments.

The results of this study demonstrate the potential of fermentation to valorize dairy and poultry byproducts, creating sustainable functional protein hydrolysates for food and feed applications.