Controlled Exogenous Enzyme Imbibition and Activation in Whole Chickpea Seed Enzyme Reactor (SER)

• Published in: Journal of food science Vol. 76; no. 4; pp. E377 - E382
• Main Authors: Kliger, Eynav, Fischer, Lutz, Lutz-Wahl, Sabine, Saguy, I. Sam
• Format: Journal Article
• Language: English
• Published: Malden, USA Blackwell Publishing Inc 01-05-2011; Wiley; Wiley Subscription Services, Inc
• Subjects: Amylases; Baby foods; Biological and medical sciences; Bioreactors; chickpea; Chickpeas; Chromatography, High Pressure Liquid; Chromatography, Thin Layer; Cicer - chemistry; Enzymes; Enzymes - metabolism; Food Handling - methods; Food industries; Food science; Fundamental and applied biological sciences. Psychology; Hydrolysis; Imbibition; infant formula; Legumes; Mathematical models; Microscopy, Electron, Scanning; Oligosaccharides - chemistry; Proteins; seed enzyme reactor (SER); Seeds; Seeds - chemistry; solid-state fermentation; Starch - chemistry; Starches; Weibull distribution; Exogenous; seed enzyme reactor (SER); Seeds; Enzyme; Imbibition; Activation; Fermentation; solid-state fermentation; chickpea; Solid state; Distribution; Infant formula; Reactor; Weibull distribution
• ISSN: 0022-1147; 1750-3841
• DOI: 10.1111/j.1750-3841.2011.02117.x

:  Chickpeas are of excellent quality (protein, vitamins, minerals, unsaturated fatty acids) and very low in phytoestrogen, making them a potentially promising source for vegetarian‐based infant formula (VBIF). However, their high starch and fiber concentration could hinder their utilization for infants. To overcome this natural shortcoming, a solid‐state “enzymation” (SSE) process was developed in which imbibition of exogenous enzyme facilitates hydrolysis within the intact chickpea seed. The process was termed seed enzyme reactor (SER). Liquid imbibition data of dry chickpeas during soaking were fitted with the Weibull distribution model. The derived Weibull shape parameter, β, value (0.77 ± 0.11) indicated that the imbibition mechanism followed Fickian diffusion. Imbibition occurred through the coat and external layers. The process was tested using green fluorescent protein (GFP) as an exogenous marker, and involved soaking, thermal treatment, peeling, microwave partial drying, rehydration in enzyme solution, and SSE at an adjusted pH, time, and temperature. Amylases, or a combination of amylases and cellulases, resulted in significant carbohydrate hydrolysis (23% and 47% of the available starch, respectively). In addition, chickpea initial raffinose and stachyose concentration was significantly reduced (91% and 92%, respectively). The process could serve as a proof of concept, requiring additional development and optimization to become a full industrial application.
Practical Application:  Chickpeas have high nutritional quality making them a potentially promising source for VBIF. However, their high starch and fiber concentration hinder their utilization. A SSE process was developed. Essentially, it turns every seed into a SER. Exogenous enzymes were transported by imbibition into the intact chickpea seed. The process consisted of: soaking and heat treatment; peeling; partial microwave drying; resoaking in enzyme solution; controlled reaction time. Commercial low‐cost enzyme(s) were used. Starch digestibility was selected as the main target due to its high concentration. The process was first tested using GFP as an exogenous marker. Amylases, and/or a combination of amylases and cellulases, resulted in significant carbohydrate hydrolysis (up to 47% of the available starch). The concentration of oligosaccharides content was also decreased. The process has the potential of circumventing relatively expensive downstream steps, such as separation spray drying, and so on.