Potential indicator enzyme s at broccoli blanching tecnology

Blanching of vegetables before freezing has some advantages as well as a number of disadvantages. Process optimization involves measuring the rate of enzyme destruction, such that the blanching time is just long enough to destroy the indicator enzyme. Eventually, peroxidases were almost universally the enzymes of choice, as they are usually the most heat-stable enzymes found in vegetables and fruits, so by the time they are inactivated no other enzymes or micro-organisms remain. But there is no evidence that peroxidases are involved in deteriorative reactions in the food. The aim of this work was to improve blanching technology in Hungarian frozen food industry with special emphasis on broccoli treatment. Instead of peroxidases, lipoxygenases were chosen to determine the adequate blanching parameters. Usually, lipoxygenases accompany lipases, so lipase activity is measured, too. On the basis of model blanching experiments, the conclusion is that lipoxygenase could be used as indicator enzyme. Being less heat stable than peroxidase, this enzyme requires shorter heat treatment, hence its inactivation should result in minimum quality deterioration and economic loss

Immunochemical analysis of buckwheat proteins, prolamins and their allergenic character

Prolamin content of buckwheat flour and processed foods was 24.2–42.1 mg/kg dry material measured by ELISA. According to in vitro results buckwheat is suitable for use in coeliac diet, although it contains some antinutritive materials, protease inhibitors and tannin. The allergenic properties of buckwheat are poorly understood. In our investigation intensity of the 24 kD protein band of buckwheat, of which allergenic activity is known has decreased, and 30–35 kD protein associations have been formed after heat treatment. Immunochemical reaction of buckwheat proteins were studied with blood specimens of coeliac and healthy persons

Characterization of buckwheat grain proteins and its products

Immunological assays demonstrate that buckwheat flour proteins present no toxic prolamins to coeliac patients. Our study proves that buckwheat has no homologous protein structure with wheat. Electrophoretograms showed that some protein bands of buckwheat proteins resemble papillionaceous (bean) proteins. The allergenic character of buckwheat was measured by competitive indirect ELISA using anti-wheat germ lectin (Wga) immune serum. Properly hulled buckwheat flour did not react with Wga immune serum, and is therefore suitable to be used in the diet of coeliac patients

Investigation of enzyme activity in Hungarian acacia and milkweed honeys

Diastase and glucose-oxidase activity was determined in 8 samples of Hungarian milkweed (Asclepias syriaca) honey and in 10 samples of Hungarian acacia (Robinia pseudoacacia) honey. The aim of the study was to compare diastase and glucose-oxidase activity of milkweed and acacia honey. Mean value for diastase was 16.28 diastase number (DN) (±2.53) in acacia honey and 24.48 DN (±5.07) in milkweed honey. Mean value for glucose-oxidase was 3.67 nmol unit g–1 (±3.31) in acacia honey and 8.24 (±4.21) in milkweed honey. The differences both in diastase and glucose-oxidase activities of the two honey types were statistically significant