Potravinarstvo Slovak Journal of Food Sciences
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The microperforated packaging design and evaluation of shelf life of fresh-sliced mushrooms
Get PDFFresh mushrooms have a very short shelf life, of 1 – 3 days because of their high respiration rate and lack of cuticles that protect the plant from external factors. In the case of fresh-sliced mushrooms, they will be more susceptible to spoilage reactions due to the increase in respiration rate as a result of a broader surface area. Conventional packaging materials can not meet the requirements for modified atmosphere packaging of fresh-sliced mushrooms. One of the techniques to extend the fresh-cut produce shelf life is the passive modification of modified atmosphere packaging technology. For highly respiring fresh-cut produce such as fresh-sliced mushrooms, the permeability properties of the polymeric materials might not be enough to provide an equilibrium gas concentration in the passive modification of modified atmosphere technology. In this case, the microperforated packaging materials can be used for passive modification of fresh-cut produce. But the microperforation process needs a design for the application of the appropriate number and diameter of microholes to meet the requirements of passive modified atmosphere packaging. For this reason in this research, the design of the microperforation process to be used in passive modified atmosphere packaging was based on the diameter and the number of microholes, and the shelf life of fresh-sliced mushrooms was determined. The samples were stored at 15 °C/80% RH, and pH, color, weight loss, textural, sensorial, and microbial analysis were performed periodically during storage. It was determined that the empirical equation used in this research can be applied to microperforated packaging design for fresh-sliced mushrooms. The shelf life of the fresh-sliced mushrooms packaged with microperforated packaging material was 8 days, while it was less than 7 days (4, 5, or 6 days) when packaged with non-microperforated packaging material. This result shows that the use of microperforated packaging material is effective in extending the shelf life of fresh-sliced mushrooms
Evaluation of the basic saccharides content in tomatoes
Get PDFSaccharides are the basic dry matter components of all fruits and vegetables. The dominant tomatoes saccharides are fructose and glucose, minor ones are sucrose but also arabinose, xylose, and galactose. The objective of this paper is to analyze carbohydrates such as glucose, fructose and sucrose in the selected tomatoes varieties intended for the direct consumption and industrial processing. We used 14 varieties and 3 newly selected tomatoes varieties. The glucose content in the studied varieties was in the range of 4.87 – 15.9 g.kg-1, the fructose content was 11.1 – 22.27 g.kg-1 and sucrose content was 0.07 – 1.73 g.kg-1. The highest fructose and sucrose content was detected in the Tomanova variety, the highest sucrose content was found out in the Bovita variety. When comparing the glucose content it was found out that the higher content on average was achieved in the varieties intended for the industrial processing (10.10 g.kg-1) than in the varieties for the direct consumption (7.96 g.kg-1). The varieties intended for industrial processing were generally characterized by higher glucose and fructose content than the varieties intended for the direct consumption. When comparing the fructose content, we found a higher average content in the varieties intended for industrial processing (15.70 g.kg-1) than in the varieties for the direct consumption (14.40 g.kg-1). In most of the studied varieties sucrose was present in low content (<1.0 g.kg-1), only in the Tomanova variety sucrose content represented more than 1 g.kg-1
Studies on the chemical composition of fruits and seeds of Pseudocydonia sinensis (Thouin) C.K. Schneid
Get PDFPseudocydonia sinensis (Thouin) C. K. Schneid. less known plant species in the Ukraine conditions, but the fruits were widely used in traditional Chinese medicine for the treatment of asthma, colds, sore throat, mastitis, rheumatoid arthritis, and tuberculosis. The content of protein, ash, and lipids in the seeds was found to be greater than in the pulp and peel. Monosaccharide analysis of neutral carbohydrate part showed the presence of two main sugars fructose and sucrose in the seeds, pulp, and peel. There is a higher beta-carotene content in the rind of the fruit than in the seeds and pulp. The total amount of fatty acids varied from sample to sample and contained mainly oleic acid, palmitic acid, linolenic acid, and linoleic acid. Linoleic acid in the seeds was 48.02% of total fatty acids, slightly less in the rind 42.70%. Palmitic acid, oleic acid, and linoleic acid in the pulp samples were 45.38, 21.32, and 14.93%, respectively. The total amount of amino acids found in the seeds was 105.0 g.kg-1 DM, including total essential amino acids (32.70 g.kg-1 DM). Glutamic acid was found in seeds to be the dominant free amino acid followed by aspartic acid and arginine in the seed. In our study, the antioxidant activity carried out by the DPPH method and measured by molybdenum reducing antioxidant power of peel, pulp and seeds were 9.41, 7.08, 6.21, and 158.81, 92.83, 78.58 mg TEAC.g-1 DM, respectively. Micro and macronutrients and amino acids predominated in the seeds, total fatty acids predominated in the pulp. The highest content of bioactive compounds (total polyphenols, flavonoid, and phenolic acid) and antioxidant activity was found in the peel. P. sinensis can be considered as a nourishing fruit with a copious potential with health-promoting roles and medicinal properties
Hygiene measures in supermarkets, retail food stores, and grocery shops during the COVID-19 pandemic in Slovakia
Get PDFThe article presents the hygiene measures that are applied in the Slovak Republic in supermarkets, food stores, grocery stores as a result of the COVID-19 pandemic situation in Slovakia. These measures have been published by the Public Health Authority of the Slovak Republic in the relevant legal regulations and are based on the decisions of the Government of the Slovak Republic, which took into account the opinions of the experts of the Pandemic Commission of the Government of the Slovak Republic. In general, these measures are based on the mask-distance-hand principle. In public areas outside and inside, it was ordered to wear masks and later wear a respirator of FFP2 class in exterior and interior, gloves on hands or disinfection of customers' hands before entering the store, observance of 2 m distance of people standing in a row at the cash registers, maximum capacity of persons in stores was determined one person per 25 m2 of sales area and later, this measure was tightened to 15 m2 of sales area. Also, to perform regular ventilation of the premises and to have as many cash registers as possible so as not to create long lines of customers. All shops were closed at 8:00 PM. In the case of shopping centers, entry is prohibited for people with a body temperature higher than 37 °C, and disinfection of hands is mandatory, wearing a mask and later wear respirators of FFP2 class is necessary. In a stricter regime, during the peak of the pandemic, there was a restriction for persons to shop food only in the nearest retail/grocery or similar place from the place of residence to the extent necessary to procure the essential needs of life
Determining the effect of replacing composite flour mixture with cassava starch on nutritional and physical properties of chicken sausages
Get PDFCassava starch extracted from cassava roots (Manihot esculanta) is a highly used ingredient for most commercial food products and has a high viscosity, water holding capacity, and binding abilities. The objective of this study was to determine the effect of replacing composite flour mixture with cassava starch on the nutritional and physical properties of chicken sausages. A scientific experiment was designed for the sausage formulation to incorporate 50% to 100% with cassava modified and native starch compared to the control sample. These samples were evaluated for sensory and textural properties. Nonparametric data obtained through sensory evaluation were analyzed using the Friedman ranking test. According to the test results, the best sample was analyzed for the nutritional toxicological composition and storage stability. According to the statistical analysis, the sample which was 50% replaced with native cassava starch showed the best sensory profile. The best sample showed average moisture, crude fat, crude protein, total solids, ash, and acid-insoluble ash content of 65.98, 7.19, 8.79, 34.02, 2.36, and 0.32 percent respectively. The starch content of the best-ranked sample was 3.12 and the cyanide content of that sample was 1.54 ppm on a dry basis. According to the microbial analysis results, the sausage sample was coliform negative and zero initial plate count was obtained. Besides, the best-ranked fresh chicken sausage was nutritionally acceptable and could keep for 14 days without adding preservatives.
Improving the method of determining the mass fraction of magnesium carbonate and the study of the chemical composition of carbonate rocks for the effective conduct of the technological process of sugar production
Get PDFThe article considers an improved method for determining the content of magnesium carbonate in the carbonate rock. An adjusted method for determining the content of magnesium carbonate was included in the complete establishment of chemical analysis of limestone, which includes the determination of moisture, impurities insoluble in hydrochloric acid, the amount of one and a half oxides of aluminum and iron, calcium carbonate and magnesium carbonate (advanced method), calcium sulfate, alkali metal oxides of potassium and sodium. The obtained experimental data were entered into a single table and summed up the material balance of all components of the carbonate rock. As a result, it was found that this technique includes the following criteria: it is the most accurate, most accessible, and cheap. The use of adjusted methods for determining the content of calcium and magnesium carbonate in limestone will make it possible to establish the objective chemical composition of the carbonate rock and avoid several technological problems. Namely, the excess of uncontrolled magnesium carbonate contributes to the formation of the liquid phase, which in turn reduces the concentration of chemically active lime and promotes the formation of melts in the lime kiln, deteriorating filtration rates, clogging the evaporating station, and so on. Therefore, having information about the real component composition of limestone, the technologist will be able to adjust the technological process in advance, which will lead to the preservation of natural resources while the quality of finished products will not decrease
The biochemical changes in legumes during high-temperature micronization
Get PDFThe article considers the change in chemical and biological characteristics in some legumes grains, under conditions of high-temperature micronization with different moisture contents during heat treatment with infrared rays. The heat treatment of grains was carried out on a laboratory apparatus with a quartz radiant infrared panel. The temperature variation in the heat treatment zone occurred due to changing the distance between the panel and the surface of grains. The grain temperature was determined using a laser thermometer, and with a timer. To determine chemical and biological characteristics, we used a special optical density metering device. We have studied: 1. The dependence of starch content on the temperature in the changing initial moisture content. We found that after 30 seconds of high-temperature micronization of, “Tsanava“ beans at a grain moisture content of 12.7%, the starch content in the grain increases from 39.65% to 40.12%, then gradually decreases, and at 18.3% moisture content, it increases from 38.71% to 41.2%, with a moisture content of 28.6% it increases from 37.36% to 42.42%. Similar processes are also observed for the beans “field red“ and “white lupine“; 2. The dependence of glucose content on the temperature in the changing initial moisture content. As the mass fraction of starch decreases, the percentage of sugar (in terms of the equivalent amount of glucose) at a moisture content of 12.7% at the initial stage increases from 1.36% to 1.46%, and then the percentage of sugar increases relatively quickly to 1.64%, at a moisture content of 18.3% it increases from 1.3% to 1.38%, and then increases to 1.51, with a moisture content of 28.6%, it increases from 1.28% to 1.35% and then increases to 1.54. Similar processes are also observed for the beans “field red“ and “white lupine“
The effect of raw pearl millet flour inclusion on the quality and formulation cost of beef sausages
No full textThis study investigated the sensory, nutritional, and physicochemical characteristics as well as formulation cost of beef sausages formulated with raw pearl millet flour (RaPMF) as an extender. Four treatments were formulated with 0%, 5%, 10% and 15% RaPMF. Ash, carbohydrate, fat, and protein contents of the beef sausages were not influenced (p <0.05) by the RaPMF. The calcium, magnesium, potassium, and pH contents were highest (p <0.05) in the 15% RaPMF beef sausages. Cooking loss was at least (p <0.05) for the 15% RaPMF beef sausages. Formulation of beef sausages with RaPMF did not affect (p >0.05) the sensory properties (week 1), water holding capacity, peroxide value, lightness (week 1), and yellowness (week 1). The formulation cost was least for 15% RaPMF beef sausages and highest for 0% RaPMF beef sausages. As a general conclusion, RaPMF improved the mineral composition of the beef sausages and reduced production costs without compromising its physicochemical and sensory properties
The attitude of Czech university students to beer consumption from microbreweries
Get PDFThe questionnaire survey was focused on the relation of university students of generation Z in the Czech Republic to beer from microbreweries. The survey involved 1,103 respondents from among Czech university students. 1,004 respondents complied with the survey conditions (they had to belong to university students and consume beer). Although 98% of beer consumed in the Czech Republic is from industrial breweries, it has turned out that the proportion of students who consume beer from industrial breweries and microbreweries is almost the same. As for beer from microbreweries, students prefer classic beers of the Pilsen type. So far, these do not circulate in beer tourism in larger quantities. The respondents agree that beer tourism will compete successfully with wine tourism. For beer tourism to develop successfully, microbreweries must also offer catering, accommodation, and other services; beer baths are in high demand at present. The economic benefits of microbreweries are in several areas – they integrate into tourist destinations, use local raw materials for beer and food preparation, create new jobs, enhance abandoned breweries and contribute to the development of rural areas
Characterization of Lactobacillus species proposed as probiotics
Get PDFAn isolated Lactobacillus from several various sources were identified depending on morphological, microscopically and biochemical tests in vitro analysis of probiotic properties that included: an ability to tolerate in different concentration of bile salt, survival in acidic conditions, their antimicrobial activity, and S-layer characterizations were carried out. It was noticed that isolates of Lactobacillus rhamnosus and L. delbrueckii have a broad activity of antimicrobial and found the isolate L. rhamnosus represented with a survival percentage 6.9% at pH 4.5 and 5.1% at pH 2.0) also L. rhamnosus (5.7% at pH 4.5 and 4.9% at pH 2.0) tolerated acidic media, Lactobacillus spp. has antimicrobial activity against all gram-positive and negative tested isolates. 70 kDa of S-layer protein bands were detected with whole-cell SDS-PAGE analysis, and it's predominant in cells of isolates which grown in MRS broth anaerobically. It was noticed that the collected Lactobacillus isolates could be used as probiotic