A reversed phase liquid chromatography-DAD method is proposed for analysis of major non-flavonoid phenolic compounds in wines. The method employed a mixture of acetic acid, water and methanol as eluents and was used to evaluate the impact of malolactic fermentation in low molecular phenolic compounds.The wines analyzed underwent different treatments, like the addition of a pectolytic enzyme or lysozyme, and the way malolactic fermentation was carried out-spontaneously or with the inoculation of two different commercial lactic bacteria.The main result observed was the disappearance of hydroxycinnamoyltartaric acids and the increase of resultant free forms, regardless the way malolactic fermentation was carried out.

The production of ethanol and beta‐galactosidase by Kluyveromyces marxianus and Saccharomyces fragilis strains grown in cheese whey was evaluated. The conditions for fermentation in 50 g/L (3.3% lactose) and 150 g/L (8.8% lactose) cheese whey were 100 rpm for 24 h at 30, 35 and 40 °C. Saccharomyces fragilis IZ 275 in 8.8% lactose at 40 °C resulted in 3.90% ethanol. Kluyveromyces marxianus CCT 3172 showed higher beta‐galactosidase, 1.10 U/mg, at 30 °C. Therefore, the choice of cultivation conditions and the most suitable species is important for obtaining high yields of the products of interest.

Milk tampering with acidified rennet whey may limit the analytical sensitivity of the reversed-phase HPLC employed for the screening of CMP and, ultimately, disguise the fraudulent addition of whey to milk. © 2017 Society of Chemical Industry.

The cheese whey shows an organic nutrient charge that can be used to obtain metabolites of interest by biotechnology of microorganisms. Thus, fermentative processes for enzyme production, in particular beta-galactosidase becomes feasible. The enzyme plays an important role in the biotech food industry to obtain milk and dairy products with low lactose content for consumption by intolerant individuals. The objective of this work was to determine the enzyme activity of the concentrated beta-galactosidase (CBG) and the permeabilized cells (PC) both obtained from Saccharomyces fragilis OZ 275. The enzyme beta-galactosidase obtained from the fermentation of Saccharomyces fragilis OZ 275 in cheese whey was used to determine the optimal conditions for the hydrolysis of lactose solution at 1% (w/v). Response Surface Methodology (RSM) by Box-Behnken Design (BBD) was employed to determine beta-galactosidase activity for such factors pH, temperature and enzyme concentration suitable for the lactose hydrolysis. Based on the statistical analysis, the optimum operational conditions for maximizing lactose hydrolysis thus optimizing the enzyme activity for CBG were, temperature 30 °C, pH 6.0 and enzyme concentration 3% (v/v) and for PC was temperature 44 °C, pH 7.0 and enzyme concentration 4% (v/v).

Yeast’s beta-galactosidase is an intracellular enzyme, through which it is possible to determine in vivo its activity as a biocatalyst in the lactose hydrolysis. Permeabilization process was used for transforming the microorganisms cells into biocatalysts with an enhanced enzyme activity. The potential application of this enzyme technology in industrial process depends mainly on the enzyme activity. Beta-galactosidase enzyme that hydrolyzes lactose, for instance, is largely dependent on the reaction time and its stability under different physical conditions, such as pH, temperature and enzyme concentration. The objective of this study was to optimize the cellular permeabilization process of Kluyveromyces marxianus CCT 3172 and Saccharomyces fragilis CCT 7586 cultured in cheese whey for lactose hydrolysis. Box-Behnken design was carried out for cell permeabilization with three independent variables, ethanol concentration, permeabilization time and temperature. The best permeability conditions for K. marxianus CCT 3172 were 27% (v v-1) ethanol, 3 min at 20ºC, with specific enzymatic activity of 0.98 U mg-1. For S. fragilis CCT 7586, a specific enzymatic activity of 1.31 U mg-1 was achieved using 45% (v v-1) of ethanol, 17 min. of reaction under 17ºC. Thus, it was concluded that cellular permeabilization with ethanol is an efficient process to determine beta-galactosidase activity.