Abstract
Pea yogurt alternatives integrate the physiological advantages of lactic acid bacteria (LAB) fermentation and the nutritional properties of pea proteins, but their development is limited by the undesirable beany off-flavor of peas. This study aims to improve the aroma profile of LAB-fermented pea milk samples by applying different starter cultures and supplementing carbohydrates. A total of 140 volatile organic compounds (VOCs) were detected using comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC×GC-TOFMS). Changing starter cultures yielded 26 critical differential VOCs, whereas glucose or lactose supplementation at different levels yielded 27 and 26 critical differential VOCs in fermentations with starters 465 and 061, respectively. The up-regulated critical differential VOCs corresponded to fermentation-generated and biotransformation-generated volatiles, whereas the down-regulated ones were mainly off-odor volatiles in pea milk. Their quantitative patterns were starter culture- and carbohydrate-dependent. Effects of starter selection and carbohydrate addition on sensory characteristics were assessed by summing the relative odor activity values (ROAVs). The creamy, sweet and pungent odors were markedly enhanced by starters used for plant-based yogurt, while glucose or lactose addition at levels of 3% or 5% (w/w) enhanced creamy odor and inhibited the green odor. These findings provide useful strategies for aroma modification of pea yogurt alternatives.