Purification and Characterization of γ-Glutamyl Transpeptidase from and Its Function on Formation of Sulfur-Containing Volatiles.

γ-Glutamyl transpeptidase (GGT) in shoot (TS) was extracted and purified through salt precipitation, ion-exchange column, and gel filtration chromatography methods. The GGT had two peptides with M.W.

Effect and mechanism of green and aldehyde aroma compounds from sweet orange on sucrose sweetness perception.

At present, there are relatively few studies on the influence of green aroma and aldehyde aroma compounds on the sweetness perception of sucrose. This study examined the effects of 11 aroma compounds from sweet orange, characterized by green and aldehyde flavors, on the sweetness of a 5 % sucrose solution. Using artificial sensory analysis and electronic tongue technology, it was found that most aromatic compounds can inhibit sweetness perception, and the inhibitory effect of trans-2-decenoaldehyde is the most significant.

Sensory properties of rehydrated Toona sinensis shoots after dehydrated by different drying methods and association with gamma-glutamyl transferase reaction.

Sulfur-containing compounds are responsible for the aroma of Toona sinensis shoot (TS). In this study, vacuum-freeze-drying (VFD), microwave-drying (MD), and hot-air-drying at 100 and 40 °C (HAD100 and HAD40, respectively), were applied to dehydrate perishable TS for preservation. VFD-TS retained most aroma of fresh/raw TS after rehydration.

Screening of Yeast in Various Vineyard Soil and Study on Its Flavor Compounds from Brewing Grape Wine.

In order to screen out suitable for table grape fermentation, and compare it with commercial in terms of fermentation performance and aroma producing substances, differences of fermentation flavor caused by different strains were discussed. In this experiment, yeast was isolated and purified from vineyard soil, 26s rDNA identification and fermentation substrate tolerance analysis were carried out, and the causes of flavor differences of wine were analyzed from three aspects: GC-MS, PCA and sensory evaluation. The results showed that strain S1 had the highest floral aroma fraction, corresponding to its high production of ethyl octanoate and other substances, and it had the characteristics of high sugar tolerance.

Effects of drying methods on the nutritional aspects, flavor, and processing properties of Chinese chestnuts.

To select a suitable drying process for using chestnut products in the food industry, this study investigated the effect of five drying methods, including natural drying, microwave drying (MD), hot air drying (HAD), freeze-vacuum drying (FVD) and microwave-vacuum drying (MVD) on the nutritional composition, flavor, and functional properties of dried chestnuts. The results indicated that the nutritional aspects and functional properties of chestnuts were enhanced by the freeze-drying process compared with the other four drying methods. The quality of the chestnuts dried using the MVD was second to the FVD.

Fast isolation of highly active photosystem II core complexes from spinach.

Purification of photosystem II (PSII) core complexes is a time-consuming and low-efficiency process. In order to isolate pure and active PSII core complexes in large amounts, we have developed a fast method to isolate highly active monomeric and dimeric PSII core complexes from spinach leaves by using sucrose gradient ultracentrifugation. By using a vertical rotor the process was completed significantly faster compared with a swing-out rotor.