Desenvolvimento de extrato de taro (colocasia esculenta) fermentado por co-cultura probiótica e seco por spray drying : otimização do processo, características físico química e viabilidade celular

Abstract

In response to current consumer demand for convenience and added value, this study developed, through optimization, a spray-dried taro extract fermented by co-culture of lactic acid bacteria (Lactiplantibacillus plantarum CCMA 0743) and yeast (Pichia kluyveri CCMA 0615). The goal was to create a non-dairy functional ingredient with symbiotic and postbiotic effects, maintaining bacterial viability above 6 Log CFU/mL. Processing conditions were defined using Response Surface Methodology (Central Composite Rotational Design), with 5.0 Log CFU/mL of P. kluyveri (fixed), ~6.9 Log CFU/mL of L. plantarum, fermentation for 18 h at 30 °C, and spray drying at 75 °C. The final product showed low water activity (0.38), hygroscopicity (4.04), and pH (3.89), with good technological performance (yield >50%, solubility >70%) and high microbial survival (L. plantarum 90.74%, P. kluyveri 47.76%). It remained stable for six months under refrigeration, with viability above 8 Log CFU/g and resistance to simulated gastrointestinal conditions. Nutritional composition was preserved, with a slight protein reduction (−1.22 g/100 g) and >50% starch retention, contributing to cell protection and a potential prebiotic effect. Fermentation enhanced bioactive compound production, especially lactic acid (10.64 mg/g) and volatiles such as hexanoic acid (437.90 mg/g), octanoic acid (103.00 mg/g), benzyl alcohol (293.40 ng/g), and phenylethanol (9580.00 ng/g), imparting sweet and floral aromas. Compounds like 3,5-octadien-2-one (531.74 ng/g) and (E)-2-nonenal (1040.00 ng/g) increased aromatic complexity. These findings highlight the potential of the fermented taro extract as an innovative, non-dairy symbiotic ingredient, offering physicochemical stability, high probiotic viability, postbiotic production, and a desirable sensory profile.