Potravinarstvo Slovak Journal of Food Sciences
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Survey of somatic cell counts and milk composition in bulk milk of ewes in dairy practice
Get PDFWe evaluated milk quality during the sheep dairy period in the year 2018. The study was performed at fifteen dairy farms with differed breeds and crossbreds under Slovakian usual practical conditions (milking and pasture). At the first and seventh farm purebred Tsigai (TS) ewes were kept, at the eight to twelve farm there were purebred Lacaune ewes (LC) and the thirteen farm were kept crossbred Improved Valachian x Lacaune ewes (IV/LC, with a higher proportion of Improved Valachian), the fourteen farm crossbred Lacaune x East Friesian ewes and the last farm were ewes of the synthetic population of Slovak dairy ewe (SD). The milk yield recording and milk sampling were performed once a month during evening milking as a part of milk recording services. The basic milk composition was determined by MilkoScan FT120 (Foss, Hillerød, Denmark) and somatic cell count was determined using a Fossomatic 90 (Foss Electric, Hillerød, Denmark) after heat treatment at 40 °C for 15 min. We found the highest incidence of SCC on farm 14 with crossbred LC/EF 3.940 x 103 cells.mL-1. Followed by farms 12 and 9 with purebred LC (SCC value of 3.318 and 2.489 x 103 cells.mL-1). Farm 7 with purebred TS reached the lowest value (831 x 103 cells.mL-1). The highest fat content was reached by the purebred TS, with gradual growth from March to July. Crossbreds and the synthetic population of Slovak dairy ewe (SD) had the lowest average fat content, which could be affected by feeding. Similar tendencies were found in protein content
A pilot plant scale of Yellow Konjac (Amorphophallus muelleri Blume) flour production by a centrifugal mill using response surface methodology
Get PDFThis study aimed at investigating the effects of polishing conditions on the physicochemical properties of polished yellow konjac flour (PYKF) with a centrifugal mill using Central Composite Design-Response Surface Methodology (CCD-RSM). Micro-mill milled yellow konjac flour (MMYKF) mass and polishing cycles were the independent variables, with four observed responses (calcium oxalate, viscosity, degree of whiteness (DoW), and glucomannan). The lower limit (-1) and upper limit (+1) for MMYKF mass in this study are 10 and 15 kg, respectively, while the -1 and +1 for the polishing cycle are three times, and seven times, respectively. The optimum prediction occurred at 10 kg of MMYKF mass and six times the polishing cycle with the following characteristics: 0.52 ±0.00% w.b. calcium oxalate, 20362.00 ±16.00 cP viscosity, 62.22 ±0.01 DoW, and 69.43 ±0.02% d.b. glucomannan content, which agreed with the verification data with p-value >0.05 for all observed responses using the paired T-test. Polishing using a centrifugal mill is feasible and promises to be scaled up to industrial scale for yellow konjac flour polishing before the wet extraction process.
The quality characteristics of sausage prepared from different ratios of fish and duck meat
Get PDFThe article aims to determine the effect of combining duck meat (Anas platyrhynchos) and freshwater fish (Hypophthalmichthys molitrix) on the quality (nutritional value, functional and technological properties, sensory attributes) of meat-containing semi-smoked sausages. The optimal version of the recipe with the highest quality indicators of semi-smoked meat sausages with duck meat and freshwater aquaculture was determined. It was found that the protein content of meat-containing, semi-smoked sausages with different ratios of duck and fish meat was 17.90% – 21.34% higher than that of the analog. A sample containing 50% duck and 30% fish has an ideal protein: fat ratio of 1:1. The following high functional properties of model minced experimental semi-smoked sausages were established: up to 72.75% moisture, water binding capacity of up to 71.47%, and water holding capacity of up to 60.60%. A comparative analysis of the rheological properties of minced meat showed that increasing the proportion of duck meat in minced meat modelling systems improves the strength of the system and increases shear stress. The addition of fish raw materials improves the elasticity of meat-containing systems. The optimal ratio of duck and fish is 50:30 for plastic and easily minced mince system. Combining duck meat with raw fish increases the stability of the emulsion to 74.8%. Analysis of the sensory parameters of the experimental sausages confirmed that the best ratio of duck to freshwater fish is 50:30
Aspects of the influence of vegetable-oil-based marinade on organoleptic and physicochemical indicators of the quality of semi-finished natural marinated meat products
Get PDFThis work evidences the expediency of marinade application based on blends of refined vegetable oils in the technology of natural marinated semi-finished meat products. Formulations of natural marinated semi-finished meat products using blends of refined vegetable oils (rapeseed, olive, and sunflower) enriched with the enzyme bromelain were developed in this work. Such formulations can provide the human body with the necessary amount of protein, released by enzymatic hydrolysis of the connective tissue proteins collagen and elastin catalyzed by the plant-based enzyme bromelain, as well as the necessary ω-3 and ω-6 polyunsaturated fatty acids, which are not synthesized in the human body but sourced from food and are one of the main structural units for many vital processes. The article presents the results of a study of organoleptic and physicochemical parameters of natural marinated semi-finished meat products from beef and pork. It is confirmed that the use of rapeseed oil and rapeseed:sunflower oil blend in a ratio of 70:30 produce the best organoleptic characteristics in both semi-finished beef and semi-finished pork: a tender, juicy texture, a pleasant taste and aroma, and an attractive appearance. It has been proven that the use of marinades based on blends of refined vegetable oils reduces the free moisture content and moisture-retaining capacity of the product, due to the presence of refined vegetable oils in the marinade, which contributes to the binding of moisture. The use of marinades based on refined vegetable oils can increase product yield. Vegetable oil, when used in meat marinade, mitigates the ill effects of acid inclusion. It dissolves well the aromas of added spices, and as it seeps through the structure of the meat, the oil gently envelops it, sealing in moisture and preventing drying out during cooking
Investigation of dependences of the morphological composition of body and amino acid composition of trout meat proteins (Oncorhynchus mykiss) on levels of the energy value of feeds
Get PDFThe article studies the effect of using complete compound feeds with different energy levels on the morphological composition of the body and the amino acid composition of trout meat proteins. The experiment aimed to establish the influence of different levels of energy nutrition of commercial rainbow trout on the morphological composition of their body and the amino acid composition of meat proteins. For this purpose, five experimental groups were formed using the analog method. The study lasted 210 days and was divided into two periods: comparative (10 days) and main (200 days). During the comparative period, the study fish consumed compound feed of the control group. During the main period, the energy level in experimental compound feeds for different experimental trout groups ranged from 16 to 20 mJ per 1 kg. It was found that with an increase in the mass of two-year-old trout, the mass of muscle tissue and the yield of edible parts probably increases. Feeding fish with an increased amount of metabolic energy (20 mJ.kg-1) resulted in a significant change in the weight of internal organs, including the heart, liver, and kidneys. Increasing the metabolic energy in the compound feeds of fish from 18 mJ.kg-1 to 19 – 20 mJ.kg-1 leads to a significant increase in bowel mass by 13.3 – 5.0%. An increase in the level of metabolic energy in rainbow trout diets from 18 mJ.kg-1 to 19 – 20 mJ.kg-1 contributed to a likely increase in the methionine content in meat. A similar pattern was observed for the tryptophan content. It was found that the content of most essential amino acids in the protein of rainbow trout meat exceeds the corresponding values in the "ideal" protein, except for the content of isoleucine and leucine, which refers them to limiting amino acids
The inhibition of wine microorganisms by silver nanoparticles
Get PDFThe presented work aimed to study the inhibition using nanoparticles produced by the green synthesis in selected acetic acid and lactic acid bacteria, which are related to viticulture. The degree of ability to eliminate silver particles produced by green syntheses was determined using the plate method on Petri dishes. This is done using two different approaches - the method of direct application of the solution to the surface of the inoculated medium (determination of inhibition zones) and the method of application using nanoparticles to the inoculated medium. Gluconobacter oxydans (CCM 3618) and Acetobacter aceti (CCM 3620T) were studied from acet acetic bacteria. The lactic acid bacteria were Lactobacillus brevis (CCM 1815) and Pediococcus damnosus (CCM 2465). The application of silver nanoparticles was always in concentrations of 0, 0.0625, 0.125, 0.25, 0.5, and 1 g.L-1. All applied concentrations of silver nanoparticles showed an inhibitory effect on the monitored microorganisms. Silver particles could be used in wine technology for their antibacterial effects, mainly to inhibit microorganisms during vinification, as a substitute for sulfur dioxide
Increasing the return on equity by financial leverage in sugar beet farms in Slovakia
Get PDFThe paper evaluates and analyses selected financial ratios of a set of farms in Slovakia in 2017. The farms are divided into two groups (sugar beet producers and sugar beet non-producers). The data used for the analysis were obtained from the National Bank of Slovakia (NBS) over the period 2009 – 2017 and the database of the Ministry of Agriculture and Rural Development of the Slovak Republic (MARD SR). Farmers generally achieve a low level of return on equity. In the paper, we analyze the development of interest rates and measure the potential effect of financial leverage, which can increase the profitability (return on equity) of the farms. Moreover, we test the statistically significant difference of selected ratios between the group of producers and non-producers of sugar beet in Slovakia. In 2017, the return on equity of sugar beet producers in Slovakia reached lower results in comparison to sugar beet non-producers. The differences in return on equity are explained by the lower level of equity per ha and thus higher indebtedness of non-producers of sugar beet
The effect of heat-moisture treatment conditions on the structure properties and functionalities of potato starch
No full textPotato starch was modified via heat-moisture treatment (HMT) under various reaction conditions. The effect of HMT on structural, physicochemical, and in vitro digestibility were investigated. HMT led to the rupture, adhesion and partial gelatinization, and agglomeration of the granules which surface became rougher, thereby increasing the particle size and resulting in the hollow structure located at the hilum of potato starch granules. XRD results showed an increased relative crystallinity and transformed crystalline structure from B-type to C-type with the extension of heat moisture treatment. FTIR spectroscopy results indicated that HMT might cause additional interactions between amylose-amylose, and/or amylose-amylopectin and/or amylopectin-amylopectin chains, which eventually leads to the increase of the mass of the carbonyl group and a hydroxyl group. HMT significantly decreased the peak viscosity, hold viscosity, and breakdown viscosity of starch, while the gelatinization temperature increased. The tHMT1, THMT100, and CHMT15 had the lowest content of RDS and there was no significant difference between the three samples, that is these three samples had the highest total content of SDS and RS
The content of silver, aluminum, and zinc in wild edible mushroom Macrolepiota procera
Get PDFThe content of selected elements (Ag, Al, and Zn) in wild edible Parasol mushroom (Macrolepiota procera Scop. Singer) collected from five sites in Slovakia – Lazy pod Makytou, Lozorno, Nemečky, Tesáre, and Zbyňov was investigated. The element analysis was determined using the ICP-OES method. The average concentrations of Ag, Al, and Zn in M. procera caps ranged as follows: 0.41 – 3.23, 16.6 – 113, and 73.4 – 111 mg kg-1 dry weight, respectively. Also, Spearman’s correlation test was used to determine the correlations between Parasol mushroom caps and stems in the content of Ag, Al, and Zn. Subsequently, the obtained data on the content of the monitored elements in M. procera caps were used for the evaluation of health risks arising from the consumption of M. procera. Although mushrooms are an important part of the diet, they are consumed mainly as a seasonal delicacy therefore, the intake of the monitored elements from the consumption of M. procera may be limited. Regular and long-term consumption of M. procera caps from investigated sites does not pose any health risks to the consumers
The chemical composition of two kinds of grape juice with medicinal plant addition
Get PDFThe safety of plant-based food with an herbal origin is a priority for producers and final consumers these days. The interest in the high biological value of the final food products enriched with herbal ingredients is rising. We focused on the study of physico-chemical composition and antioxidant activity of two kinds of grape juice with medicinal plant addition in our study. We used 2 varieties of grapes - Welschriesling and Cabernet Sauvignon, six species of medicinal plants - Calendula officinalis L., Ginkgo biloba, Thymus serpyllum, Matricaria recutita, Salvia officinalis L., and Mentha aquatica var. citrata in our experiment. There were14 samples prepared, two of them were control samples and 12 samples were treated with medicinal plants. We tested each of the selected parameters triplicate with an interval of one week. We evaluated the results statistically in 4 levels of significance p <0,01, p <0,001, p <0,0001 and p <0,00001. The content of fructose, glucose, dry matter, density, malic acid, pH, potential alcohol, total acids, and total sugars in the treated samples was significantly lower compared to the control sample, which was probably due to the degree of dilution of grape juice with extracts gained from medicinal plants. The antioxidant effect was demonstrably higher in the samples enriched with medicinal plants than in the control samples. The highest antioxidant effect was measured in the second test in the samples with the addition of Thymus serpyllum (80.93 % - white grape must, 82.33 % - blue grape must), Calendula officinalis L. (79.29 % - white grape must, 80.49 % - blue grape must) and Ginkgo biloba (79.10 % - white grape must, 83.3 % - blue grape must). Generally, we found out that the selected medicinal plants increase the biological quality of grape juice