4results about How to "Keep it sweet" patented technology

The application discloses a mutant of single-chain sweet protein with high thermal stability and a gene of the mutant, wherein the mutant is obtained by mutating isoleucine (I) at the 5th position, glutamic acid (E) at the 23rd position, isoleucine (I) at the 26th position, tyrosine (Y) at the 65th position, glycine (G) at the 83rd position and asparagine (N) at the 90th position in the amino acid sequence shown in SEQ ID NO. 1 to alanine (A), arginine (R) and aspartic acid (D) respectively. m The Tm of the mutant of single-chain sweet protein with high thermal stability is increased by more than 19.4 DEG C, and the sweetness is maintained.

The invention belongs to the field of steviol sugar, and particularly relates to a preparation process of low-sweetness steviol sugar. The invention relates to a steviol sugar preparation process, which comprises: (1) extracting a stock solution, crushing stevia rebaudiana dry leaves, and screening with a 40-70 mesh sieve to obtain stevia rebaudiana powder; the stevia rebaudiana powder and neutral purified water are put into an extraction device to be subjected to water immersion extraction at 40-45 DEG C for 12-48 h, and an extraction stock solution is obtained; (2) concentration and fermentation: centrifuging the extracted stock solution, concentrating until the dosage ratio of stevia rebaudiana powder to neutral purified water is 1: (5-18) g / mL, and then putting into a fermentation tank for natural fermentation; (3) regulating the sugar degree, and preparing the fermented solution into a solution with the sweetness of 24 + / -1; and (4) preparing powder particles, decoloring, and spraying to prepare the powder particles. The prepared steviol sugar has the advantages of being low in calorie, moderate in sweetness, good in stability and the like, the steviol sugar is low in sweetness, almost does not contain calorie, cannot cause violent fluctuation of blood sugar, and can avoid excessive calorie while meeting the requirement for sweetness.

The invention relates to the technical field of food beverages, in particular to a formula and a preparation process of a hydrolyzed protein liquid beverage, the formula of the hydrolyzed protein liquid beverage comprises protein, a supplement and a conditioning agent, the supplement is selected from one or more of calcium hydroxybutyrate, leucine, isoleucine and valine, and the conditioning agent is selected from one or more of calcium hydroxybutyrate, leucine, isoleucine and valine. The regulator is selected from one or more of gamma-aminobutyric acid, glycine, taurine, 5-hydroxytryptamine and beta-aminobutyric acid; peptide molecules contained in the hydrolyzed protein liquid beverage disclosed by the invention can quickly enter blood circulation through intestinal tracts; for a patient in a hypoproteinemia state before and after an operation, rapid and effective protein supplement is crucial, postoperative recovery is promoted, and the occurrence rate of complications is reduced; for traumatic injuries such as fracture, burn and the like, timely supplement of high-quality protein components is a key for accelerating wound healing and tissue repair.

The application discloses a mutant of single-chain sweet protein with high thermal stability, a gene and engineering bacteria, wherein the mutant is a mutant of an amino acid sequence shown in SEQ ID NO. 1, and the isoleucine (I) at the 5th position is mutated into glutamic acid (E), the glutamic acid (E) at the 23rd position is mutated into alanine (A), the isoleucine (I) at the 26th position is mutated into arginine (R), the tyrosine (Y) at the 65th position is mutated into isoleucine (I), the glycine (G) at the 83rd position is mutated into glutamic acid (E) and the asparagine (N) at the 90th position is mutated into glutamic acid (E); the application is based on structural analysis and protein stability calculation aided design, and a mutant of single-chain sweet protein with high thermal stability is obtained by site-directed mutagenesis of the single-chain sweet protein; compared with the single-chain sweet protein, the mutant of single-chain sweet protein with high thermal stability has a T m which is increased by more than 18.4 DEG C and keeps the sweet taste.