Decomposition of ochratoxin A by heat and gamma-irradiation.

Up to 50% of initial amounts of 2 and 100 ng/ml ochratoxin A were decomposed after gamma-irradiation of solutions in water, in 2% aqueous NaCl or an aqueous solution of 2% NaCl and NaNO2. Ochratoxin A in these solutions was not decomposed, however, after heating at 20, 121 or 135 degrees C for 15 min.

Sensory effect of the sorption of some flavouring agents on blood plasma protein preparations.

Presented investigations included the assessment of the sorption of selected flavouring agents on blood plasma preparations. The following aromatizing spices were used: marjoram, dried garlic, lovage, pepper, nutmeg and smoke flavour preparations. Thresholds of recognition of the spices mentioned above were determined at the temperatures of 10, 20 and 40 degrees C. For different quantities of protein a definite influence of temperature was determined. Similarly the quantity of protein exerted influence upon the intensity of the sorption of the odour of spices. The analysis of the results obtained in the investigations allows an interpretation of the character of binding between the flavouring agents and the protein preparations. It turned out that this process is the resultant of chemisorption and physical sorption.

The influence of radapertization upon some sensory properties of black pepper.

Radapertization may be used as an effective method for sterilization of spices. A possible influence of irradiation upon the sensoric qualities should be considered in this context. Therefore the objectives of the work were: --to determine the influence of the irradiation of pepper upon its sensoric quality --to determine the qualitative changes of volatile chemical substances under the influence of the irradiation of pepper --to determine correlation between changes resulting from irradiation and the sensoric quality of pepper. The spice was irradiated with doses of 10, 20, 40 and 60 kGy. Thresholds of recognition and difference were determined. It was established that the quantity of the dose is related to the values of thresholds mentioned above. The larger the dose was the less intensive the flavour became and the higher the thresholds. These interdependences were written in a form of mathematical formulas. A significant influence of irradiation upon the decrease of the quantity of essential oils and carbohydrates was noticed. These relations were also presented in a form of mathematical formulas. The work provides evidence for the fact that there is a relation between the results of sensoric assessments and the chemical characteristics (the content of volatile carbonyl, sulphuric and nitrogenic substances). Correlation between these factors was determined on the basic statistical analysis of the results obtained during our investigations.