Potravinarstvo Slovak Journal of Food Sciences
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Microbiological, chemical and organoleptic evaluation of fresh fish and its products irradiated by gamma rays
Get PDFThe present study evaluated the microbiological, chemical, and organoleptic aspects of irradiated fresh fish and its products to extend their shelf life. Fresh fish and its products were irradiated at three doses (1.5, 3.0, and 4.5 kGy) used for preservation to study the effects of irradiation on their microbiological properties, fatty acid composition, and organoleptic properties. Irradiated fresh bolti fish, smoked herring, and smoked mackerel were evaluated microbiologically, chemically, and organoleptically. Radiation treatment not only reduced the counts of aerobic bacteria, fecal streptococci, molds, and yeasts but also destroyed all the Staphylococcus aureus cells, improving the hygienic quality of the fresh and smoked fish samples. Irradiation increased the peroxide, acid, and thiobarbituric acid values, but they remained within acceptable levels. No new fatty acids or other artifacts due to irradiation were observed. Irradiation of 4.5 kGy greatly reduced the organoleptic quality scores of fresh bolti fish, indicating that the optimum radiation dose for this fish was 3.0 kGy. Smoked herring and mackerel could be irradiated with up to 4.5 kGy without adverse effects on their organoleptic properties
The study of rapeseeds ash composition in the conditions of the agroecological experiment
Get PDFA comparative analysis of the seeds ash composition of the breed Rif (Brassica napus L.) rapeseeds grown in the Lipetskaya region was held. The plants were grown in the conditions of the agroecological experiment using mineral (NPK and zeolite) and organic (hen droppings) fertilizers. 6 variants of the experiment were studied – the plants are grown without fertilizers application (the control); the mineral fertilizer (N60:P60:K60) separately and together with zeolite (5 t.ha-1); the zeolite in pure form (5 t.ha-1); hen droppings (5 t.ha-1) separately and together with zeolite (5 t.ha-1). We studied the accumulation of 9 basic elements (in mass %) contained in Brassica napus. seeds ash using the method of energy-dispersive X-ray spectroscopy. The accumulation order of the elements was determined: P ≈ K > Mg ≥ Ca > Mo > S > Zn > Mn > Fe. The proportion of P fluctuated from 10.852 to 11.855 mass %; the proportion of K – from 9.933 till 12.343 mass %. The rapeseeds contained Mg, Ca, and Mo in similar concentrations within the range of 4.0 -5.8 mass %. The combined application of zeolite with organic fertilizer ensured the accumulation of the minerals in the seeds. Correlations between the elements were established. High correlation between elements K and Mo was found (r = 0.96); P and Mg (0.86); P and Fe (r = 0.94); C and Mo (r = 0.86). The positive effect of the combined organic-mineral fertilizers with poultry farms wastes usage on the mineral elements accumulation in rapeseeds was stated. It is noted that the accumulation of P, Ca, Mo, and S in rape seeds leads to a decrease in Zn
The effect of kefir-spirulina on glycemic status and antioxidant activity in hyperglycemia rats
Get PDFDiabetes mellitus (DM) is a metabolic disorder characterized by chronic hyperglycemia. It is caused by impaired insulin secretion or by insulin receptor insensitivity. DM and its complications are often related to increases in the level of oxidative stress. Spirulina is a nutrient-dense food that contains an abundance of antioxidant compounds. In combination with kefir, it may serve as both a nutrient-rich diet and an antioxidant agent that can prevent complications of diabetes. This study aims to investigate the nutritional content of kefir-spirulina and its effect on glycemic status and antioxidant activity in streptozotocin-nicotinamide (STZ-NA) induced diabetic rats. A total of 30 male Sprague Dawley rats were divided into five groups: normal control (K1), diabetic control (K2), pioglitazone treatment (K3), kefir combined with 1% spirulina treatment (P1), and kefir combined with 2% spirulina treatment (P2). All rats were induced by STZ-NA, except for the normal control. Before and after the 28 days of intervention, blood samples were taken and analyzed for fasting plasma glucose, postprandial glucose, and SOD activity. The nutritional content, ethanol content, and total antioxidant capacity of kefir-spirulina were also analyzed. The diabetic rats that were fed with kefir-spirulina (P1 and P2) had a significant decrease in both fasting and postprandial plasma glucose (p <0.001) compared to the diabetic control rats. The decrease of plasma glucose in K2 is comparable to the control rats treated with the diabetic drug pioglitazone (K3). The activity of SOD in diabetic rats fed in P1 and P2 were higher (p <0.001) than in untreated diabetic rats (K2). The IC50 of kefir-spirulina was 42 – 43 ppm. It was concluded that kefir combined with spirulina has high nutrition and antioxidant capacity, which is proven to be capable of controlling glycemic status and enhancing antioxidant status in a diabetic rat model
The nutritional characteristics and acceptability of Baobab (Adansonia digitata L) pulp as nutrient concentrate substitute in custard powder
Get PDFMicronutrient deficiency in the human diet is of serious concern in developing nations. The utilization potential of Baobab pulp (BP) as a micronutrient source in custard formulation was evaluated. Custard powder was formulated from corn-starch, salt, flavor, colorant, and a commercial nutrient concentrate (NC) using a standard recipe, as a control sample. The nutrient concentrate was substituted by 20 – 50% of Baobab pulp in custard formulation. Custard powder was characterized by chemical, physicochemical, pasting, and sensory properties, using standard procedures. Substitution of Baobab pulp for nutrient concentrate in custard formulation resulted in a significant (p ≤0.05) increase in the crude protein (2.23 – 3.67%), fat (1.49 – 2.40%), fiber (2.95 – 4.85%), and ash (2.21 – 3.63%) contents of custard powder. The vitamins A, C, and Beta-carotene contents of Baobab pulp-fortified custard varied (p ≤0.05) significantly. Substitution of Baobab pulp for nutrient concentrate increased the mineral composition (Calcium (1.16 – 5.75 ppm), Magnesium (1.09 – 1.83 ppm), Potassium (0.81 – 2.68 ppm), and Iron (0.12 – 0.39 ppm)) of custard samples significantly (p ≤0.05). The addition of Baobab pulp in the custard powder formulation enhanced its chemical composition and sensory attributes. The enhancement level increases with an increase in the proportion of baobab pulp
Research of hop polyphenols impact on malt hopped wort aroma formation model experiments
Get PDFCurrently, a lot of research is being done on the flavoring compounds of hops. However, much less attention has been paid to the aroma formation considering the hop polyphenol different groups by various methods at the wort hopping stage. Therefore, the main goal of the research is an impact of hopping conditions on the polyphenolic compounds, when the hop is extracted variously into both wort and water to better understand extraction conditions, mechanisms, and factors as well as aroma formation considering various groups of polyphenols. As shown the hop variety, boiling time, and treatment type affect the hop polyphenols amount extracted into the wort. Aromatics varied upon a hop variety and wort boiling time accompanying a positive softening effect regarding aroma formated from malt wort compounds comparing to hopped aqueous extracts. The research proved the most noticeable pH (7 and above) impact on aroma formation caused by the polyphenol conversion. As also shown the first time, a temperature and acidic pH doubled the rutin amount, as well as the best extraction of the prenylflavanoid isoxanthohumol, was achieved by boiling at an alkaline medium pH. The results obtained indicate that various hydrophilic amino acids containing in the wort can stabilize polyphenols affecting the quality indicators of beer produced from different grain raw materials
Phenolic content and antioxidant activity of Echinocystis lobata (Mich.) Torr. ET Gray (Cucurbitaceae)
Get PDFEchinocystis lobata (Mich.) Torr. et Gray extracts were investigated for their bioactive compounds and their potential for natural antioxidant properties. In vitro antioxidant activity of methanol, ethanol, and water extracts were evaluated by 1,1-diphenyl-picrylhydrazyl (DPPH) radical scavenging activity. Total phenolic content (TPC) and total flavonoid content (TFC) of fruits and seeds were determined. TPC is a fairly constant value and varies weakly both among the different organs of Echinocystis lobata and among the geographical locations of the populations studied. Like other invasive species, Echinocystis lobata is superior to many other plants in terms of the total amount of flavonoids contained in its fruits and seeds. The dried fruits contain more flavonoids than the seeds. Seeds from Slovak populations have higher flavonoid content than those from Russian populations. The results demonstrated that Echinocystis lobata can be a good source of natural antioxidants and have a great potential for commercialization, especially in the pharmaceutical industry
The role of gambeir filtrate and red palm oil in the formation of canna starch based-functional edible film
Get PDFThis study aims to analyze the role of gambier filtrate and red palm oil in the formation of functional edible film and to determine whether the gambier filtrate and red palm oil are synergistic or antagonistic in the formation of functional edible films. The study design used a factorial randomized block design with two treatment factors and each treatment consisted of three levels, namely: gambier filtrate concentration (A): 20, 30, and 40% (v/v) as well as red palm oil concentration (B): 1.2 and 3% (v/v). The observed parameters were thickness, elongation percentage, water vapor transmission rate, antioxidant activity, and antibacterial activity. Gambier filtrate and red palm oil were capable to improve the antioxidant and antibacterial properties of canna starch-based edible film. Gambier filtrate plays a role in increasing the elongation percentage, thickness, and water vapor transmission rate of edible film
An improved method for determining the mass fraction of calcium carbonate in the carbonate bedrock
Get PDFIn the article it is offered to enter in the technological audit of the lime department of sugar factory the adjusted technique of the definition of the maintenance of calcium carbonate in carbonate breed. For this purpose, a complete chemical analysis of limestone was performed, which includes determination of moisture content, impurities insoluble in hydrochloric acid, the amount of one and a half oxides of aluminum and iron, calcium carbonate (advanced method), and magnesium carbonate, calcium sulfate, alkali metal oxides, potassium, and sodium. The obtained experimental data are summarized in one table and the material balance of all components of carbonate bedrock is summarized. The proposed method made it possible to obtain objective data on the component composition of the carbonate material. This, in turn, avoids many technological problems, namely to reduce the formation of melts in the lime kiln, improve the filtration of juices, increase the ability of lime to chemically interact with water, reduce the volume of water on the juicer etc. Thus, the use of the recommended method for determining calcium carbonate (CaCO3), as part of the technological audit, will allow early adjustment of the process, which will give maximum energy and resource savings, as well as increase the level of environmental friendliness of the enterprise
Consumption dietary sources of lycopene, lutein, and zeaxanthin among young adults living in megapolis
Get PDFCarotenoids are natural antioxidants, affecting apoptosis, absorbing active forms of oxygen, and improving visual performance through their blue light filtering capabilities. Lutein and zeaxanthin are carotenoids of the macular pigment that play a significant role in protecting against age-related macular degeneration (AMD), cataracts, and diabetic retinopathy. We analyzed the dietary sources of lycopene, lutein, and zeaxanthin of young adults living in a megapolis. We analyzed 431 food frequency questionnaires and used two different criteria for comparison: age (groups A1 and A2) and season (groups S1, spring, and S2, autumn). Raw red tomatoes and eggs are the main sources of carotenoids for the majority of respondents regardless of age and season. Significant differences between age groups were found for parsley, carrot, cheeseburger, and spring onion. Foods with high levels of carotenoids (tomato juice, pumpkin, spinach, and sprouts) were absent in the diets of most of the study participants. Watermelons and persimmons are seasonal sources of lycopene, lutein, and zeaxanthin. Dietary sources of carotenoids are present in insufficient quantities in the diets. Foods with high levels of lycopene, lutein, and zeaxanthin are absent or only occasionally included in the diet
The effect of carbon dioxide on the quality of the mushrooms
Get PDFMushrooms' quality may be significantly changing depending on their type, strain, growing cycle, packing, cooling, postharvest handling (PHH), and conditions of storage. This work aimed to define the influence of the type and mushrooms' strain, the regime of the PHH by carbon dioxide on their preservation (marketability, loss of weight (LW)), changes in the chemical substances, and physiological activity (intensity respiration (IR) and heat release (HR)). Mushrooms Agaricus bisporus (AB) (strains ІБК-25 and ІБК-15) and Pleurotus ostreatus (PO) (strains НК-35 and Amycel 3000) were used for testing. Three regimes of treatment by CO2 with a concentration of 20% were applied: 2 h; 12 h and 22 h. The control was the mushrooms without treatment by CO2. Changes in the chemical substances such as dry matters (DM), protein nitrogen (PN), and ascorbic acid (AA) in the researched mushrooms were observed. The best result of mushroom preservation was provided by the regime of CO2 treatment during 12 h. The yield of marketable AB was 94.9% (IBK-25) and 94.2% (IBK-15) comparison to control 93.5%, and 92.5%, respectively. The regime of PHH 2 h almost has no influence but 22 h harmed this indicator. PHH of mushrooms by carbon dioxide was promoted to preserve the DM and increasing concentration of CO2 was supplied better results. Thus, DM at the end of storage in the AB of strain IBK-25 depend on the regime were 8.5, 8.6, and 8.4%, against – 8.3% in the control variant. Significant quantitative changes in the PN and AA as a result of treatment by CO2 were not established. PHH also affected the IR and HR. The increased duration of treatment by CO2 inhibited the intensity of physiological processes in the mushrooms. But, as in previous cases, the best result was provided PHH by 20% CO2 during 12 h. Similar trends of treatments effect by carbon dioxide were observed in the mushrooms of PO