Physicochemical, textural and rheological properties of probiotic yogurt fortified with fibre-rich pineapple peel powder during refrigerated storage

Health benefits associated with dietary fibre consumption have shifted its applications towards inclusions into food products. This work aimed at exploring the influence of adding pineapple peel powder (PPP) as a fibre source on physicochemical, textural, theological, and microstructural attributes of probiotic yogurt during refrigerated storage for 28 days. Skim milk with or without PPP or inulin as a control was fermented by yogurt cultures with or without addition of the probiotic cultures consisting of Lactobacillus acidophilus (ATCC (R) 4356 (TM)), Lactobacillus casei (ATCC (R) 393 (TM)) and Lactobacillus paracasei spp. paracasei (ATCC (R) BAA52 (TM)). PPP supplementation at 1% remarkably reduced fermentation time of milk co-fermented with probiotic organisms. Syneresis level in probiotic yogurt with PPP (1.16% at day 1) was comparable with the prebiotic-inulin and increased during storage. However, firmness and storage modulus in both plain and probiotic yogurts were lowered significantly with PPP addition. The reported information on physicochemical and structural attributes of probiotic yogurts with PPP could guide the dairy industry to utilize pineapple peel discarded as processing waste to close the fibre gap by developing a new synbiotic product with comparable attributes to inulin, a commercial prebiotic. (C) 2015 Elsevier Ltd. All rights reserved.