β-galactosidase (EC 3.2.1.23) is one of the widely used enzymes for lactose-free milk production and whey permeate treatment. Enzymes can be obtained from microorganisms, plants and animals. Nowadays, microorganisms are becoming an important source for production of commercially available enzymes, which are of great interest and offer several advantages such as easy handling and high production yield. The aim of this review was to summarize findings of research articles on the application of commercially available β-galactosidase preparates in dairy industry, to analyse and compare the most suitable β-galactosidase commercial preparates for lactose hydrolysis. The results showed that the main factor to choose an appropriate β-galactosidase for lactose hydrolysis was reaction condition. Enzymes from microorganisms contain a wide range of optimal pH from 4.0 (Penicillium simplicissimum and Aspergillus niger) to 8.5 (Bacillus subtilis). The greatest commercial potential has enzymes obtained from fungi (Aspergillus oryzae and Aspergillus niger) and yeasts (Kluyveromyces lactis and Kluyveromyces fragilis). Fungal origin enzymes are more suitable for the hydrolysis of lactose in acid whey due to its acidic pH but yeasts origin enzymes for milk and sweet whey. In the study, commercial preparates from different suppliers with the purpose to analyse their lactose hydrolysis potential and give more detailed characteristics of each preparate advantages and drawbacks were also summarized.

Due to the ever increasing demand for energy resources, more and more attention is being paid to renewable energy resources. One such potential resource is lignocellulosic biomass that can be treated to acquire a carbohydrate rich substrate for further use in producing biofuels such as bioethanol or biobutanol. In this study, birch (Betula pendula) chips were used in fast pyrolysis to acquire bio-oil. This bio-oil was further hydrolyzed in pressurized reactor Parr 4554 to produce a carbohydrate rich feedstock. Hydrolysis conditions were optimized. Several conditions − three different temperatures (111, 121, 131 °C) and four different sulfuric acid concentrations (0.05, 0.1, 0.2, 0.5 M) were tested. The optimal conditions were 121 °C with 0.2 M sulfuric acid as a catalyst that allowed to acquire a solution with the total glucose concentration being 6.6% that can be further used as a feedstock for biofuel acquiring.

The effect of some ingredients on stability of butter during its storage time has been investigated in order to better evaluate the functionality of confectionery. The research established that butter does not contain enough free fatty acids, derived as a result of hydrolysis, to decrease the number of mould and group of Enterobacteriaceae, but they hinder the growth of yeast and aerobic mesophilic and facultative anaerobic microorganisms. The quality of the products can be provided and propagation of microorganisms can be hindered by the comounds that are not traditional preservatives, such as vanilin and glucose syrop. A 10% glucose syrup additive worked as the facilitator of the development of microorganisms because it increased growth of aerobic mesophilic and facultative anaerobic microorganisms, 50% of glucose syrup additive worked as the procrastinator of the development of microorganisms.

Oats contain more beta-glucan (2-7%) than other croppers. Beta-glucan is the most essential water-soluble dietary fibre. It lowers cholesterine level in blood as well as stimulates elimination of carcinogens from the body. In order to enlarge possibilities of use of oats in a diet, they can be separated in water-soluble and insoluble fractions. The aim of the present study is to determine the amount of beta-glucan in hydrolysed oat soluble and insoluble fractions. Gelatinized, hydrolysed and steeped oatmeal prior to hydrolyse, which was separated in water-soluble and insoluble fractions, was used in experiments. Not more than 6% of gelatinized (non-hydrolysed) oatmeal dry matter dissolved in water. The outcome of fermentative hydrolysed dry matter of water-soluble oatmeal was 40-52%. The content of beta-glucan in soluble and insoluble oatmeal fraction was determined by using McClearly method. The content of beta-glucan fraction of gelatinized oatmeal decreased for 78% in comparison to the content of beta-glucan in oatmeal used in the experiments. The content of beta-glucan in the soluble fraction of hydrolysed oatmeal decreased for 8.1% to 9.2%, and increased for 35-42% in the insoluble fraction if compared with the content of beta-glucan in oatmeal.

The major wheat flour constituent, which determines the dough quality, is gluten. Oatmeal has higher biological value due to amino acid composition and content if compared to other cereals, but the technological properties of proteins are not as good as the ones of wheat flour. Oat products can be used in bread making although the increased amount of additives shows negative influence on bread texture, elasticity, volume, taste, and flavour. The method is developed for hydrolysed oatmeal separation in soluble and insoluble fractions, thus extending the oatmeal application possibilities. The aim of the current research was the investigation of influence of hydrolysed oats insoluble fraction on wheat dough rheological properties. The obtained results proved that in case hydrolysed oats insoluble fraction additive was used, water adsorption was increased by 63.8%-66.4% and dough stability time was changed from 4.8 to 10.0 min. The negative influence on dough development time and dough softening degree was observed. The farinograpgh quality index was within acceptable limits (less than 120 FU), if the oat additive of 10% and 15% was used. It is possible to obtain dough with better rheological properties if the hydrolysed oats insoluble fraction additive is 15% from flour mass.