The current scientific research is focused on the Lucuma powder. We were determined the moisture equilibrium data (adsorption and desorption) at three different temperatures: 10°C, 25°C and 40°C and relative humidity from 0.11 to 0.90, using the static gravimetric method of saturated salt solution. The results showed that the sorption capacity decreased when the temperature increases in the conditions of constant water activity. We were used four different mathematical models – modified Chung–Pfost, modified Oswin, modified Halsey and modified Henderson for description of isotherms of Lucuma powder. According to obtained experimental data, we were recommended the modified Halsey model for description satisfactorily the sorption isotherms of powder.

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The present study determined the physico-chemical parameters of the exotic fruit jujube (Ziziphus jujube mill) of Bulgarian origin – pH of 4.62, refractometric dry matter of 31.6 %, dry matter (in weight) of 36.78 %, TTA (total titratable acidity) – citric acid – of 0.67 %, 0.70 % malic acid, 65.95 % moisture, 0.78 % fibre, 1.41 % protein, 23.65 % carbohydrate, 0.24 % fat and energy value of 428.44 kJ/102.4 kcal. Equilibrium moisture content and monolayer moisture content were established for desorption concerning eight water activities in the 0.1 0.9 range and the temperatures of 10 °С, 25 °С and 40 °С. The coefficients of the modified Oswin, Chung-Pfost, Halsey and Henderson models were obtained statistically. The modified Halsey model is recommended as a description of the desorption isotherms of jujube (Ziziphus jujube mill) since it corresponds to the criteria for model assessment and suitability. Via BET model linearization, the values of the monolayer moisture content for desorption at the temperatures of 10 °С 5.41 % d.b., 25 °С – 4.65 % d.b. and 40 °С 5.08 % d.b were determined.

Einkorn wheat is a grain crop characterized by the ability not to accumulate heavy metals from the soil. Besides, it is rich in selenium. Jerusalem artichoke is rich in inulin. From the combination of these two types of flour (einkorn wheat and Jerusalem artichoke), bread can be produced for people for who suffer from type 2 diabetes. It is proved that consuming bread enriched with Jerusalem artichoke for two months every day significantly reduces the glycaemic index of patients suffering from type 2 diabetes. To provide these patients systematically with fresh bread, the bread dough freezing technique is suggested. We have studied how the storage time of dough enriched with a flour mix (100 % einkorn wheat flour and Jerusalem artichoke flour) in the frozen state influence the modes of the main technological operations in the production of bread made of frozen dough, namely, defrosting, the time of increasing the temperature of the dough up to the operational level, the duration of the final fermentation and of baking. It has been established that the storage time of the dough in the frozen state reduces the duration of defrosting (which differs by 91 min. from that of the reference sample). However, there is a reverse effect, too, for the rise of the temperature of the dough to the operational level and for the final fermentation. The duration of the two above-mentioned operations is determined simultaneously. It is 5 min. more, compared with the reference sample. It has been established that the storage time of frozen dough does not affect the duration of baking. By the organoleptic indicators, the bread from the frozen dough is very similar to the reference sample.

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