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Introduction: This study aimed to determine the optimal processing conditions to produce stable starch-based hydrogels by high-pressure processing (HPP) via response surface methodology. Methods: The experiments were carried out with different starch suspensions, namely rice, corn, wheat, and tapioca starch, at a concentration in the range of 10%-40% w/w, processed at a pressure level of 600 MPa and holding times between 5 min and 15 min. Gel formation was assessed by determining the gelatinization extent and structuring level of the samples. Results and discussion: The results demonstrated that starch/water ratio and holding time had a significant impact on gel formation in HPP treatments. Various degrees of gelatinization were observed in the treated samples due to the water absorption capacity of the starch and the molecular interactions between water and starch occurring during gelatinization. Moreover, a highly structured hydrogel formed at starch concentrations higher than 25% (w/w), whereas when starch concentrationwas less than 20%(w/w) lower-structured hydrogels formed, as confirmed by the values of the efficiency index measured. Completely gelatinized, highly structured, and stable HPP hydrogels were obtained from starch solutions treated at the optimized processing conditions. [ABSTRACT FROM AUTHOR]

Introduction: This study aimed to determine the optimal processing conditions to produce stable starch-based hydrogels by high-pressure processing (HPP) via response surface methodology.Methods: The experiments were carried out with different starch suspensions, namely rice, corn, wheat, and tapioca starch, at a concentration in the range of 10%–40% w/w, processed at a pressure level of 600 MPa and holding times between 5 min and 15 min. Gel formation was assessed by determining the gelatinization extent and structuring level of the samples.Results and discussion: The results demonstrated that starch/water ratio and holding time had a significant impact on gel formation in HPP treatments. Various degrees of gelatinization were observed in the treated samples due to the water absorption capacity of the starch and the molecular interactions between water and starch occurring during gelatinization. Moreover, a highly structured hydrogel formed at starch concentrations higher than 25% (w/w), whereas when starch concentration was less than 20% (w/w) lower-structured hydrogels formed, as confirmed by the values of the efficiency index measured. Completely gelatinized, highly structured, and stable HPP hydrogels were obtained from starch solutions treated at the optimized processing conditions.

Poria cocos mushroom is widely used as a food and an herb in East Asian and other countries due to its high nutritional value. Research has demonstrated that Poria cocos polysaccharides (PCP) are the major bioactives and possess antioxidation, anti-inflammation, immunoregulation, and other health promoting properties. However, the efficient preparation of PCP has been a challenge, particularly in large scale for industry. Herein, we investigated the biotransformation of PCP from Poria cocos, catalyzed by β-glucanase from Aspergillus niger and focused on optimizing the most four influencing parameters: Temperature, time, pH, and enzyme dosage in this study. After numerous optimizations with the assistance of response surface optimization methodology, we have established that the optimal conditions for the biotransformation PCP preparation were as following: Enzymolysis temperature 60 °C, time 120 min, pH 5.0 and enzyme dose 20 mL. Under these conditions, the extraction yield of PCP reached as high as 12.8%. In addition, the antioxidant activities of PCP were evaluated by reducing power assay and 1,1-diphenyl-2-picryl-hydrazyl, superoxide anion, and hydroxyl radicals scavenging assays. Resulting data showed that PCP presented outstanding antioxidant capacity. Thus, these findings indicate that PCP could be produced as a natural antioxidant for further development.

Poria cocos mushroom is widely used as a food and an herb in East Asian and other countries due to its high nutritional value. Research has demonstrated that Poria cocos polysaccharides (PCP) are the major bioactives and possess antioxidation, anti-inflammation, immunoregulation, and other health promoting properties. However, the efficient preparation of PCP has been a challenge, particularly in large scale for industry. Herein, we investigated the biotransformation of PCP from Poria cocos, catalyzed by β-glucanase from Aspergillus niger and focused on optimizing the most four influencing parameters: Temperature, time, pH, and enzyme dosage in this study. After numerous optimizations with the assistance of response surface optimization methodology, we have established that the optimal conditions for the biotransformation PCP preparation were as following: Enzymolysis temperature 60 °C, time 120 min, pH 5.0 and enzyme dose 20 mL. Under these conditions, the extraction yield of PCP reached as high as 12.8%. In addition, the antioxidant activities of PCP were evaluated by reducing power assay and 1,1-diphenyl-2-picryl-hydrazyl, superoxide anion, and hydroxyl radicals scavenging assays. Resulting data showed that PCP presented outstanding antioxidant capacity. Thus, these findings indicate that PCP could be produced as a natural antioxidant for further development. [ABSTRACT FROM AUTHOR]