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The effect of phospholipase A1-catalyzed degumming on the phosphorus content, the retention rate of oryzanol, and total tocopherols and tocotrienols of dewaxed rice bran oil was investigated with comparison to water degumming and citric acid degumming. The fatty acid composition of dewaxed rice bran oil was also studied by gas chromatography. The phosphorus content of dewaxed rice bran oil after phospholipase A1-catalyzed degumming could be decreased from 332.5 mg·kg−1 to 9.3 mg·kg−1 with the citric acid dosage of 0.10%, high shearing rate of 23000 rpm, chelation time of 60 min, NaOH dosage of 1.5 mole equivalent to the amount of citric acid, reaction temperature of 50°C, and total water dosage of 2.5%, while the phosphorus content of dewaxed rice bran oil after water and acid degumming was 120.5 mg·kg−1 and 66.4 mg·kg−1, respectively. The retention rate of oryzanol and total tocopherols and tocotrienols was 97.58% and 96.81% for phospholipase A1-catalyzed degumming, 91.44% and 85.98% for water degumming, and 92.85% and 87.75% for acid degumming. There was no obvious change in fatty acid composition. The results indicated that phospholipase A1-catalyzed degumming was an effective method since it could decrease the phosphorus content to the required level and provide high retention rate of oryzanol and total content of tocopherols and tocotrienols without obvious change of fatty acid composition.

BACKGROUND: With an increasing demand for edible protein, research on new extraction methods is attracting more attention. The effects of such methods on functional properties are important. The present study aimed to evaluate the effect of ultrasound‐assisted extraction on the extraction efficiency, structure, and the emulsifying properties of peanut protein isolate (PPI). RESULTS: Ultrasound‐assisted extraction significantly improved extraction efficiency and shortened the processing time. The nanostructure, molecular weight distribution, and particle size of PPI were altered by ultrasound‐assisted extraction. The emulsifying properties of the PPI from ultrasound‐assisted extraction were significantly improved compared with alkaline extraction. Peanut protein isolate had lower molecular weight fractions, higher levels of hydrophobic amino acids, and the highest fluorescence intensity with ultrasound intensity, temperature, and time of 3.17 W cm−3, 35 °C, and 30 min, respectively. These contributed to the higher emulsifying activity index and emulsifying stability index of the PPI emulsions. The uniform distribution of droplets and smaller particle size of the PPI emulsions was also observed. CONCLUSION: The results suggested that ultrasound can be used to induce the conformational changes to modify the interfacial association between protein‐oil phases, thereby improving the emulsifying properties of peanut protein. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

ABSTRACT Four enzymes, alcalase, neutrase, bromelain and papain, were used individually to hydrolyze proteins in rice residue. The process conditions were optimized by response surface methodology (RSM). Under optimal conditions hydrolyzate yields generated with neutrase, alcalase, bromelain and papain were 49.3, 56.7, 30.8 and 16.6%, respectively. Molecular weight distributions of the hydrolyzates were analyzed by high-performance liquid chromatography. The results showed that hydrolyzate generated with neutrase and alcalase had smaller polypeptides than those with bromelain and papain. Compared with alkaline extraction, the solubility of the hydrolyzates treated by enzyme was greatly improved. Antioxidant activities of the hydrolyzates were also evaluated in this study. The induction time of the hydrolyzate generated with alcalase was longer than those with other enzymes. Emulsifying activities of the hydrolyzates generated with different enzymes were significantly different and that prepared with alcalase exhibited the best emulsifying activity among all other hydrolyzates. PRACTICAL APPLICATIONS Rice residue is a by-product of extracting starch and other carbohydrates from rice. The residue is rich in protein, but is normally used as animal feed because of the poor solubility. In this research, alcalase, neutrase, bromelain and papain were used individually to hydrolyze proteins in rice residue. RSM was used to establish models to estimate the optimum conditions and predict the hydrolyzate yield at different conditions. Under the optimum conditions, hydrolyzates were prepared and the functional properties of the products generated with different enzymes and extracted by alkaline were compared. The solubility and other properties of rice protein hydrolyzates were greatly improved, so it could be used for nutritional supplementing, functional enhancement, etc. Therefore, this article has practical value, which provided the theoretical basis for the application of rice residue. This text should highlight the uses of rice residue, either actual or potential. [ABSTRACT FROM AUTHOR]

Summary The protein and starch fractions of field pea (Pisum sativum L.) are potentially a source of novel ingredients for food processing. As part of research to elucidate the functional properties of field pea proteins, the pilot scale extraction of proteins has been undertaken. Two different approaches have been used and the recoveries of protein compared. The first involved extraction with a salt solution followed by decanting and clarification to remove solids. The solution was then further concentrated and salt removed by ultrafiltration and diafiltration. The second procedure was based upon alkaline extraction followed by decanting and recovery by isoelectric precipitation and neutralisation. Both spray drying and freeze drying methods were employed. The protein isolates have been compared and characterised with respect to solubility, chemical composition and to electrophoretic patterns. Overall, the proteins extracted with salt exhibited better physical properties than proteins extracted with alkali, in terms of colour and particle size. The solubilities showed little variation and the electrophoretic patterns were similar. Freeze drying resulted in isolates with darker colour compared with spray drying. [ABSTRACT FROM AUTHOR]