Preparation of konjac glucomannan/casein blending gels optimized by response surface methodology and assessment of the effects of high‐pressure processing on their gel properties and structure

• Published in: Journal of the science of food and agriculture Vol. 98; no. 11; pp. 4160 - 4167
• Main Authors: Zhang, Fusheng, Fan, Qiao, Li, Hongyun, Chen, Hourong, Zheng, Jiong
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.08.2018; John Wiley and Sons, Limited
• Subjects: Amorphophallus - chemistry; Blending effects; blending gel; Casein; Caseins - chemistry; Chemical bonds; Diet; Food Handling - instrumentation; Food Handling - methods; Food industry; Food processing industry; Fourier transforms; gel property; Gels; Gels - chemistry; Hardness; high‐pressure processing; Hydrogen bonding; Infrared spectroscopy; konjac glucomannan; Mannans - chemistry; Optimization; Organic chemistry; Plant Extracts - chemistry; Polysaccharides; Pressure; Pressure effects; Properties (attributes); Proteins; Response surface methodology; Spectroscopy, Fourier Transform Infrared; Structural damage; casein; response surface methodology; high-pressure processing; gel property; konjac glucomannan; blending gel
• ISSN: 0022-5142; 1097-0010
• DOI: 10.1002/jsfa.8937

BACKGROUND In order to improve the compatibility of polysaccharide–protein mixtures and enhance their performance, a response surface methodology was used to optimize the preparation conditions of konjac glucomannan/casein blend gel. Moreover, the effects of high‐pressure processing (HPP) on the gel properties and structure were also investigated. RESULTS The optimal preparation parameters were a temperature of 60 °C, a total concentration 40 g kg−1, and a dietary alkali concentration 5 g kg−1. Under these conditions, the experimental value of hardness was 38.7 g, which was close to the predicted value. HPP increased gel hardness by 161–223% and led to a more compact structure at 200–600 MPa/10 min, while a hardness increase of ∼120% and damaged structure were observed at 600 MPa/30 min. Fourier transform infrared spectroscopy showed that noncovalent interactions are likely the most important factor in the modification of gel hardness; indeed, hydrogen bonding interactions in the gels are enhanced when subjected to HPP, but are weakened at 600 MPa/30 min. COUCLUSION Protein–polysaccharide complexes with excellent properties could be obtained through this method, with broad application prospects in the food industry. © 2018 Society of Chemical Industry