Ten different Persian walnut cultivars were examined for their compositional data, including eight Hungarian and two introduced varieties. Oil content and fatty acid composition were determined, as well as oxidative stability (indicated by induction time). Antioxidative capacity, total polyphenol measurements, and individual phenolic compounds were also determined. Not only dry samples but fresh and stored samples were included in this study. Large differences were found among the varieties within these parameters, for example in oxidative stability, which contributes to antioxidative capacity. In conclusion, the nutritional value of Hungarian walnut cultivars was the same or even higher than those of foreign ones.

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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.

The combination of gas chromatography and mass spectrometry (GC/MS), using an apolar capillary column and electron impact ionization (EI+), made it possible to determine the eritadenine content of Shiitake mushroom after silylation at microgram levels. The sample preparation consisted of only two steps, namely extraction of eritadenine from the mushroom and silylation with N‐methoxy‐N,O‐bistrimethylsilyl carbamate (BSMOC) at 80°C. This simple and rapid method has good precision and accuracy, is useful for quantitation of eritadenine content in caps, stems and mycelium of different species of mushrooms. © 1998 John Wiley & Sons, Ltd.

Nowadays, demand for products which beyond the overall nutritional value have a feature that protects the consumers health, have increased. Several studies have proved fruit juices can become suitable carrier or medium for probiotic organisms. Therefore the aim of our study was to investigate the possibility of the probiotication of sour cherry juice by lactic acid fermentation with probiotic starter culture. In the fermentation 9 Lactobacillus strains were used and two cultivars of sour cherry as raw material. The pH adjustment and supplement of nutrients were necessary and to reach the recommended probiotic cell count we also investigated the effect of dilution of sour cherry juice. Due to the optimized combination of the pH adjustment, supplementation and dilution, the investigated strains reached the desired 9 log cfu mL−1 cell density in sour cherry juices, however a significant difference was observed between the number of viable cells of some Lactobacillus strains. In the Újfehértói fürtös sour cherry L. acidophilus La-5 (9.43 log cfu mL−1), while in the Petri species L. acidophilus 150 (9.60 log cfu mL−1) resulted in the highest probiotic cell number. The lactic acid fermentation can increase the phenolic compounds, but in case of the bioactive compounds significant differences were not general between the strains.

Anti-nutritive components in multi resistant potato cultivars were investigated in relation to conventional and organic farming for three years. Glycoalkaloids, nitrate, nitrite, asparagine, and glutamine contents of tubers were examined. Farming technology was found not to have an effect on the level of glycoalkaloids, which was influenced mostly by the genotype and season. Nitrogen fertilisation caused significant increase in nitrate, asparagine, and glutamine contents as compared to organic farming. Nitrite content was found to be more independent of farming technologies than nitrate. Tubers of cultivar Rioja had the lowest nitrate content irrespective of season or technology. In conclusion, the absolute amount and changes of different anti-nutritive components of potato tubers were influenced differently by the technology, genotype, and season in a complex manner. Organic farming had no effect on the glycoalkaloid content, but the nitrate levels had a tendency to be lower compared to conventional farming. This can be seen as a positive effect of organic farming.

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The combination of lactofermentation and enzyme-treatment (Rohament-PL as endo-polygalacturonase and the mixture of Rohament-PL and Rohalase 7069 as cellulase) of sliced carrot and orange juice resulted in a homogeneous product, with pleasant organoleptic features, after 18 h fermentation period. Two ways of inoculation were applied with Lactobacillus plantarum. The addition of Rohament-PL, even at 150 mg kg -1 concentration, simultaneous inoculation with Lactobacillus plantarum (circumstances: 28 °C, 80 r.p.m. shaking) promoted the growth of lactobacilli. By 42 h fermentation time LAB count increased up to 3.2-4.8u10 9 cm -3 . Furthermore the surface colour of the samples was more intensive (higher L-, a-and b-values) than without Lactobacillus plantarum inoculation. The application of Rohament-PL (50-100 mg kg -1 ) resulted in a homogeneous carrot puree, the combination of Rohament-PL (150 mg kg -1 ) and Rohalase 7069 (150 mg kg -1 ) in the process gave a more fluid product, as proved by the lower specific viscosity values.