Storage Stability, Gastrointestinal Release and Sensory Properties of Cookies Incorporated with Protein-based Moringa oleifera Leaf Extract microcapsule

Abstract

Moringa oleifera leaves have been known for the numerous nutritional and health benefits. In this study, the bioactive compounds present in M. oleifera leaf extract were extracted and encapsulated in soy protein isolate (SPI) and pea protein isolate (PPI). The M. oleifera microcapsules (MM) produced were incorporated in cookies on replacement basis at 2.5%, 5% and 10% (w/w), respectively with wheat flour. Total polyphenolic contents (TPC) of M. oleifera microcapsules with soy protein isolate (MM-SPI) cookies were 0.72, 0.89 and 1.11 mg GAE/g at 2.5%, 5% and 10%, respectively and the TPC for M. oleifera microcapsules with pea protein isolate (MM-PPI) cookies were 0.74, 0.84 and 0.93 mg GAE/g at 2.5%, 5%, and 10%, respectively. The antioxidant scavenging properties (DPPH) of incorporated cookies for MM-SPI cookies were 0.70, 0.84 and 1.22 mg TE/g at 2.5%, 5 % and 10%, respectively and MM-PPI cookies were 0.43, 0.52 and 0.63 mg TE/g at 2.5%, 5% and 10%, respectively. The storage stability of MM cookies showed slight levels of degradation in the TPC and the percentage TPC retained after 90 days storage were 96.84%, 80.65% and 49.26% for cookies with 5% MM-SPI, 5% MM-PPI and 0% MM cookies, respectively. The gastrointestinal stability of the MM cookies showed a higher released rate at the intestinal system. The MM were able to mask M. oleifera greenish colouration, although at 10% incorporation of MM in cookies; the beany flavour of SPI and PPI were intense, which led to low sensory evaluation scores.