Effect of spray-drying or fermentation on the solubility and carbohydrate profile of chickpea hydrolysates for beverage formulation

Abstract

Powder beverage bases were developed using extruded and hydrolyzed chickpea supernatant through freeze-drying. This study evaluated the effects of spray-drying and adjuvant incorporation for producing powders and supernatant fermentation with LAB strains prior freeze-drying on the carbohydrate composition, structural integrity, and physical properties of chickpea beverage base powders. All powders had low insoluble (<0.2%) and soluble (<3%) dietary fiber contents due to processing. Starch content decreased below 9.49% when using adjuvants and 10.61% during fermentation. Both treatments also reduce raffinose oligosaccharide content below 6.1 mM/100 g. Spray-drying and adjuvant addition promoted a more amorphous starch structure, enhancing solubility, while fermentation induced more crystallinity, according to FTIR data. Microscopy showed small particle clusters and lack of birefringence. SEM images revealed starch granule damage from both fermentation and spray-drying, with more uniform particles in spray-dried powders. Spray-drying resulted in the smallest particle sizes (455-457 nm) and higher absolute zeta potential (8.12-9.51), indicating greater stability. Fermentation had the opposite effect, negatively impacting the colloidal system stability. Samples had a pH close to 6, except fermented powders with a pH of 3.6, affecting colloidal stability. Fermentation significantly reduced solubility but without practical implications, as all samples had solubility values over 93%, which is desirable for beverage-based powders. Spray-drying and fermentation altered the carbohydrate profile and structure of the powders. Fermentation prior producing powders may provide benefits, but it slightly decreases the system stability. Spray-drying can be used instead of freeze-drying to produce stable chickpea base powders that are highly soluble.