The debittering effect of extracellular enzymes from Bacillus subtilis ACCC 01746 was studied using soybean meal as a substrate for solid-state fermentation(SSF).Results showed that B.subtilis produces proteases and c...The debittering effect of extracellular enzymes from Bacillus subtilis ACCC 01746 was studied using soybean meal as a substrate for solid-state fermentation(SSF).Results showed that B.subtilis produces proteases and carboxypeptidase in the early stage of SSF(0–8 h).Proteases are dominant and can hydrolyze the soybean protein into long-chain peptides with mild bitterness.Carboxypeptidase production is dominant at 8–16 h SSF,at which point soybean protein is further hydrolyzed and bitterness is enhanced.The strain then produces additional carboxypeptidase after 16 h,and bitterness is reduced.We compared the amino acid composition of the hydrolysates from soybean protein isolates to that of the fermented liquid of SSF.In the hydrolysates from soybean protein isolates that exhibit strong bitterness,62.81%of amino acids are hydrophobic and occur in the form of peptides.In the fermented liquid from soybean meal,16.22%of amino acids are hydrophobic and are mainly present in the form of free amino acids.The bitterness of fermented soybean hydrolysate is reduced from 5 to 0 when fermented for 24 h,suggesting that B.subtilis can effectively reduce bitterness,possibly due to the carboxypeptidase.Enzyme analysis shows that B.subtilis excretes carboxypeptidase during growth.The amino acids phenylalanine,alanine,tyrosine,and leucine at the C-terminal of the soybean bitter peptides in hydrolysates are cleaved in the presence of carboxypeptidase,resulting in complete debitterness.展开更多
[Objective]To explore the debittering technique for concentrated orange juice. [Method] Active carbon was used to debitterze naringin and limonin from con-centrated orange juice. [Result] Through single-factor experim...[Objective]To explore the debittering technique for concentrated orange juice. [Method] Active carbon was used to debitterze naringin and limonin from con-centrated orange juice. [Result] Through single-factor experiment and sensory as-sessment, the optimum debittering technique was identified as temperature at 20 ℃, active carbon at 35 g/L （soluble solid content 50.5%）, processing time of 20 min. Under above conditions, the removal rates of naringin and limonin in concentrated juice were 49.5% and 73.5% respectively. [Conclusion] Debittering endows the con-centrated juice with gentle flavor and mild taste.展开更多
基金supported by Grain&Corn Engineering Technology Research Center,State Administration of Grain(GA2017004)Science and Technology Research Project of Henan(172102110205)Henan University of Technology:Integration of Science and Education(30)
文摘The debittering effect of extracellular enzymes from Bacillus subtilis ACCC 01746 was studied using soybean meal as a substrate for solid-state fermentation(SSF).Results showed that B.subtilis produces proteases and carboxypeptidase in the early stage of SSF(0–8 h).Proteases are dominant and can hydrolyze the soybean protein into long-chain peptides with mild bitterness.Carboxypeptidase production is dominant at 8–16 h SSF,at which point soybean protein is further hydrolyzed and bitterness is enhanced.The strain then produces additional carboxypeptidase after 16 h,and bitterness is reduced.We compared the amino acid composition of the hydrolysates from soybean protein isolates to that of the fermented liquid of SSF.In the hydrolysates from soybean protein isolates that exhibit strong bitterness,62.81%of amino acids are hydrophobic and occur in the form of peptides.In the fermented liquid from soybean meal,16.22%of amino acids are hydrophobic and are mainly present in the form of free amino acids.The bitterness of fermented soybean hydrolysate is reduced from 5 to 0 when fermented for 24 h,suggesting that B.subtilis can effectively reduce bitterness,possibly due to the carboxypeptidase.Enzyme analysis shows that B.subtilis excretes carboxypeptidase during growth.The amino acids phenylalanine,alanine,tyrosine,and leucine at the C-terminal of the soybean bitter peptides in hydrolysates are cleaved in the presence of carboxypeptidase,resulting in complete debitterness.
文摘[Objective]To explore the debittering technique for concentrated orange juice. [Method] Active carbon was used to debitterze naringin and limonin from con-centrated orange juice. [Result] Through single-factor experiment and sensory as-sessment, the optimum debittering technique was identified as temperature at 20 ℃, active carbon at 35 g/L （soluble solid content 50.5%）, processing time of 20 min. Under above conditions, the removal rates of naringin and limonin in concentrated juice were 49.5% and 73.5% respectively. [Conclusion] Debittering endows the con-centrated juice with gentle flavor and mild taste.
