Evaluation of plant-based milk quality and stability: A commercial analysis

Abstract

The plant-based food market is rapidly growing and evolving which is nowhere more evident than in the alternative dairy space. Despite dairy milk consumption decreasing, plant-based milk alternatives have seen a steady increase in consumption over the past two decades. As plant-based milk development continues to innovate, new products flood the market from a variety of diverse plant sources such as oat, hemp, and pea. With such varied plant-based milks available, there is a gap in our understanding of what defines quality and therefore stability in these products. This study set out to elucidate factors that influence plant-based milks' quality and stability through testing commercial samples using sensory evaluation and analytical techniques. In an effort to identify attributes that define plant-based milk quality, the sensory profile of almond milk was analyzed throughout accelerated and ambient shelf-life studies and the almond milk was screened for markers of quality using gas chromatography-mass spectrometry. Sensory evaluation found that the almond milk lost its characteristic almond aroma and flavor over storage which aligned with a decrease in benzaldehyde in the analytical data. To better understand the potential reactions causing the degradation of plant-based milks, a variety of plant-based milks were screened for their stability against lipid oxidation using OxipresTM. Soymilk and oat milk were less prone to lipid oxidation than almond milk which is likely a result of their unsaturated fat content. Active research is focusing on testing the performance of antioxidants in plant-based milks to determine their ability to control lipid oxidation as well as any potential flavor modulating effects. While every plant-based milk is unique, the results of these studies indicate that factors that influence their quality and stability include the inherent stability of the plant source as well as the formulation of the plant-based milk.