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- ДокументANALYSIS OF THE EXISTING METHODS AND SPECIFIC FEATURES OF DRYING SHIITAKE MUSHROOMS(2021) L. Avdieieva, E Zhukotskyi, H. Dekusha, S. IvanovThe paper reviews and analyses the advantages and disadvantages of the existing technologies of drying shiitake mushrooms, which are a valuable source of bioactive polysaccharides, vitamins, antioxidants, etc. The findings presented in the paper show how various drying methods and their thermotechnological operating parameters affect the mechanostructural properties, chemical composition, content of aromatic substances and other compounds of mushrooms. It has been demonstrated that the traditional convection drying of shiitake in the temperature range 50–60°C allows maximum preservation of phenolic compounds, organic acids, nucleotides, sulphuric aromatic substances, and enhances the unique aroma of the mushroom. Radiation drying has such advantages as lower shrinkage of dried shiitake mushrooms, a higher coefficient of rehydration and higher hardness, and the drying time reduced by 66% compared with freeze-drying. Vacuum drying makes it possible to obtain high quality products, but significantly increases the duration of the process and reduces the content of aromatics. Radiation drying combined with hot air allows obtaining a dry form of shiitake rich in protein and bioactive polysaccharides and having high physicochemical properties, and reduces the duration of the process by 37.5% compared with convection drying. Spray drying of shiitake mushrooms is highly practical economically and allows organising industrial manufacture of high-quality dry mushroom powder in large volumes. It is characteristic of this drying method that its temperature effect on the product is slight, which makes it possible to preserve thermolabile bioactive substances. When using spray drying, it is advisable to add dextrin additives. This improves the structuring and moisture-conducting properties of the suspensions and their thermal stability, and helps preserve the unique aroma of shiitake mushrooms due to encapsulation of aromatic compounds. Studying the effect of various drying methods on the physicochemical properties of shiitake will lead to improving the existing technological processes and will make it possible to obtain products with desired properties.
- ДокументRESEARCH INTO THE THERMOPHYSICAL CHARACTERISTICS OF MUSCLE AND ADIPOSE TISSUES IN THE FREEZING–THAWING PROCESS(2021) O. Dromenko, V. Potapov, M. Yancheva, V. Оnishchenko, V. Bolshakova, A. InzhyyantsThe paper presents a study of the thermophysical characteristics of meat systems based on minced beef and pork with different morphological composition in the freezing–thawing process, and those of model systems based on minced beef with addition of adipose tissue (raw fat). The method used to detect and compare the thermodynamic changes consisted in determining the effective specific heat capacity by freeze-thaw thermograms and was based on a set of informational parameters related to it (cryoscopic temperature, cryoscopic interval of temperatures, specific heat of phase transition in the cryoscopic temperature interval, change of enthalpy in the interval of temperatures of the sample tested, proportion of moisture that changes its physical state in the cryoscopic temperature interval). It has been shown that the morphological structure of meat (the ratio of muscle, connective, and adipose tissues) significantly affects the thermophysical parameters of meat systems during freezing and defrosting. It has been found that under the conditions of a freeze–thaw cycle, an increase in the content of connective tissue leads to a higher proportion of moisture that changes its physical state in the cryoscopic temperature interval, while an increase in the adipose tissue content in a meat system reduces the moisture that changes its physical state in the cryoscopic temperature interval. When adipose tissue was introduced into meat systems, the freezing process resulted in a higher rate of formation of ice crystals and a lower rate of moisture migration from cells to the intercellular space, and crystal formation became a controlled process. When manufacturing semi-finished frozen meat products, regulating the ratio of muscle and adipose tissues makes it possible to influence the stability of the properties of meat systems in the technological cycle “freezing – storage – thawing” and to create products with the required functional, technological, and thermophysical parameters. This research can be a basis for developing the recipe compositions and technological parameters of manufacturing semi-finished frozen meat products and finished products based on them
- ДокументOptimisation of conditions for deacetylation of chitin-containing raw materials(2021) O. Pavlova, M. TrusovaThe paper describes the differences between chitosan and chitin, and reviews works by foreign scientists on obtaining chitosan from various raw materials. Methods of modifying chitosan and obtaining combined sorbents have been analysed. It has been studied whether chitosan is applicable in the technology of wines and alcoholic beverages as a sorbent. The purpose of the study was determining the optimal conditions of the deacetylation stage to obtain chitosan with the best sorption properties from Aspergillus niger biomass. A three-factor experiment has been carried out. It involved obtaining 27 samples of chitosan using sequential four-step acid-base hydrolysis under various conditions of the deacetylation stage. The deacetylation process was optimised under alkaline conditions depending on the alkali concentration, processing temperature, and exposure. For each of the samples obtained, the adsorption activity, specific surface area, and distribution coefficient in the sorbent–sorbate system have been determined. The degrees of deacetylation of all chitosan samples have been determined by potentiometric titration. The study has resulted in determining the optimal conditions for the deacetylation stage: processing temperature 110–130°C, sodium hydroxide concentration 27–36 g/dm3, exposure 45 to 65 minutes. The sample deacetylated at the temperature 120 °C, alkali concentration 30 g/dm3, and exposure 45 minutes has shown the best adsorption activity values: the adsorption activity for methyl orange 347.96 mg/g, the specific surface area of the sorbent samples 0.52·105 m2/g, the distribution coefficient in the sorbent–sorbate system 3.29·10-3 ml/g. This sample had the highest degree of deacetylation, 43.6%. The sample has been analysed using IR spectroscopy, and its main characteristic frequencies have been studied. It has been concluded that the sample obtained was equivalent to the reference chitosan
- ДокументTHE BOUILLON TABLES FROM TURKEY: DETERMINATON OF CIS-TRANS FATTY ACID PROFILES BY CAPILLARY GAS CHROMATOGRAPHY(2021) Harun DıramanNowadays, commmercial bouillon tablets are mostly used as a flavor enhancer substant or an instant product in Turkish cuisine. As chemical structure, Trans FAs are unsaturated fatty acids having at least one double bond in its trans geometric configuration. Trans FA are occured by the partial hydrogenation of vegetable oils in the manufacturing of margarine and vegetable shortening. In this study, industrially produced commmercial bouillon tablet (n=14) samples from Turkey were analyzed by capillary (DB 23 column) gas chromatography method and an under controlled temperature oven programm with particular emphasis on cis–trans fatty acid profiles. The bouillon samples were collected as two goups (first group containing animal additives [AAB n=12] and second group including vegatable additives [VAB n=2]). There is no detailed information on fatty acid (FA) compounds, including trans fatty acids (TFAs), of consumed several commercial boullions in Turkey. There is no “trans fatty acid-free” declaration on various bouillon labels in Turkey. Large variations were observed among the cis–trans FA profiles of the boullion samples from Turkey,despite the fact that the samples are produced in the same production conditions.The palmitic (PAM) levels (predominant cis saturated FAs for all samples) of AAB samples (32.63–44.44%) were more high rather than the VAB samples (47.62–50.64%). Other major saturated FAs for AAB and VAB samples were determined stearic ( (5.28–9.90% AAB and 6.33–6.73% VAB), lauric (0.19– 5.84% AAB and 1.13–1.30% VAB) and myristic acids (0.86–2.61% AAB and 1.39–1.45% VAB).The changes of oleic (OLA) acid (from other predominant cis monounsaturated FA) of VAB samples (30.75–33.45%) were high than those of AABs (12.64–29.35%). The ranges of LO, an essential /nutritional fatty acid and the predominant FA of PUFAs, and PUFAs of AAB – except two samples– commercial bouillon samples (0.45–9.82% and 0.45–9.97% ) were low rather than VAA samples (7.97–8.14% and 8.14–8.35 %). Conjugated Linoleic (CLA) FAs, having nutritional FAs having anti-carcinogenic, antioxidative and anti-atherosclerotic effects, were determined in small amounts for only six samples (0.03% to 0.06% ). Elaidic acid (C18:1 trans acid) content, the mainly trans FA in all boullion, was within the range of 20.00–27.32% in the AAB samples, and it was significantly higher than the range in VAB samples (0.08–0.14%). Total trans fatty acids (TFAs) were another important major (second) FAs for all bouillon samples. The changes of Trans/Cis ratio ranged between 0.26 and 0.50 for AAB samples but VB samples has a little values from 0.002 to 0.003. Turkish vegetable boullion. samples have low total trans FA contents (0.19–0.26%) than the animal boullion samples (20.19–28.78%).There are a large variation and significant (P<0.05) differences were statistically determined among major cis FAs (PAM, SA, OLA, LO and LN) and their involved parameters (SFAs, MUFAs and PUFAs). The consumed several commercial boullions in Turkey were classified and characterized chemometric method (Principal Component Analysis, PCA) based on some fatty acid profiles and their parameters. Applying PCA to the all bouillon samples data determined the percentage of total variance explained by the first two PCs were 49.3% and 21.8% (totally 71.1%), respectively.
- ДокументEFFECT OF CHITOSAN PRETREATMENT ON THE QUALITY OF STRAWBERRIES DURING COLD STORAGE(2021) A. Blahopoluchna, N. LiakhovskaThe paper is focused on improving the technology of storing strawberries. It has been investigated how pretreatment of berries with aqueous solutions of low-molecular-weight chitosan of three concentrations (0.1%, 0.3%, 0.5%) affects the quality parameters of strawberries during refrigeration. The treated berries and the reference (untreated sample) were stored in 500 g perforated plastic containers at 0±2°C for 14 days. It has been found that strawberries treated with chitosan solutions had significantly smaller weight loss than the reference. At the end of storage, this parameter was 9.7% in the reference and 7.0–8.6% in the treated berries. It has been established that the respiration rate of the strawberries decreased sharply on the first day, which was caused by refrigerated storage, and continued to decline until the end of storage. Finally, this parameter attained the value 3.3 mg CO2/kg-1h-1in the reference and 2.2–3.0 mg CO2/kg-1h-1 in the treated berries. The hardness of the strawberries at the end of storage was 0.10–0.14 kg/cm2. The change in the lustre level of the berries has been observed. It has been established that on the 14th day of storage, the surface of the untreated berries was dull. The best characteristics have been observed for treatment at the chitosan concentration 0.5%. The effect of chitosan films on the sensory characteristics of berries has been investigated. It has been found that the pretreatment did not impair the taste of the berries. The results of the tasting evaluation indicate that the taste, aroma, and colour were better in the variants with the treatment concentrations 0.3 and 0.5%. However, as for the appearance and consistency, the experts preferred the berries treated at the concentration 0.5%. After two weeks’ storage, the strawberries have been found to be damaged by four fungal diseases. The infections found in the samples were Botrytis cinerea (grey mould), Rhizopus stolonifer (black mould), Whetzelinia sclerotiorum (white mould), and Penicillium spp. It has been established that pretreatment of strawberries with chitosan solutions reduces the development of phytopathogenic diseases. It has been shown that chitosan-based edible coatings have a positive effect on strawberries, increasing their shelf life and improving their quality. A conclusion has been drawn about the technology of application of chitosan solutions and about their concentrations.
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