DETERMINATION OF RATIONAL ENERGY-SAVING PARAMETERS OF PROTEIN HYDROLYSIS AS A PREPARATORY STAGE BEFORE SPRAY DRYING

Abstract

One of the effective ways to intensify technological processes and reduce energy consumption is the use of enzyme preparations, including proteases. Directed proteolysis allows to regulate physicochemical parameters (foam and gel formation, viscosity reduction, increase of antioxidant, antidiabetic action, etc.) of solutions with hydrolysed proteins. Each enzyme is characterised by certain optimal conditions for the reaction, but proper selection of enzyme preparations available on the domestic market today and studies of their action under different technological regimes on protein substrates or their mixtures, allows to increase energy efficiency, manufacturability and economic feasibility of this process.

The aim of the research is to determine the rational energy-saving parameters of proteolysis of whey protein concentrate (WPC), soy protein isolate (SPI) and their mixtures by proteases that are available at the domestic market.

Methods. Determination of the degree of protein hydrolysis was determined by spectophotometric method at light absorption change (λ=280 nm).

Results. The dependence of the degree of hydrolysis (DH) for WPC and SPI on the enzyme concentration (1–5%) at a process duration of 60 min was determined experimentally. The highest DH for SPI was obtained by the action of Protamex, which exhibits rather high enzyme specificity to soya proteins. When the enzyme concentration of 5%, DH values for SPI reached 70–75%, for WPC the highest was obtained by the action of Protease C, namely DH=60–65%. Increase of protease concentration up to 10% does not lead to significant increase of hydrolysis products of both proteins.

The highest DH of the protein mixture WPC:SPI at a ratio of 70:30, respectively, was achieved using Protease C (DH=73–75%). The results of proteolysis of this protein mixture by Protamex and ORBAproteo showed somewhat lower and similar values (DH=63–65% and DH=63%, respectively).

When a mixture of WPC and ISP was hydrolyzed at a ratio of 50:50, the highest DH was found in the sample that was hydrolyzed with Protamex and was DH=72–75%, while with the action of ORBAproteo and Protease C, the degree of hydrolysis was lower, namely DH=68–71%.

In all samples, rapid accumulation of hydrolysis products occurred during the first 60 min, after which protein breakdown slowed down significantly, so further hydrolysis was not advisable.

Conclusions.

The development of technologies for products containing proteins in hydrolyzed form remains a promising direction in the domestic food industry.

Depending on the type of enzyme preparation, its concentration and the duration of the process, it is possible to obtain а mixture of peptides and free amino acids, the degree of hydrolysis of which is DH=65–75%. They can be used as a protein component of dry powder concentrates in the development of technologies for special or dietary products.