Qualitative parameters of non-traditional types of vegetables

The main aim of this study was to determine selected quality indicators of non-traditional types of leafy vegetables. Mizuna (Brassica rapa japonica), Chinese mustard (Brassica juncea), edible chrysanthemum (Chrysanthemum coronarium) and arugula (Eruca sativa) belonged among the selected species of vegetables. During the one-year experiment, spring and autumn sowing was carried out for these species of vegetables. The measured quality parameters were the content of nitrates and ascorbic acid. Sampling was done in the morning and in the laboratory, the samples were further processed according to the type of determination. To determine the content of nitrates and ascorbic acid, leaves were removed from plants. The filtrate from the leaves was then prepared. Determination of nitrates and ascorbic acid was carried out using a special test strip and device Rqflex plus 10. The results of measurement of both sowing varieties were compared. Total nitrate content was higher up to 22% in plants sown in the autumn except edible chrysanthemum (Chrysanthemum coronarium). The highest content was recorded in arugula (Eruca sativa), which was recently implemented to the studies of the European Union and for which there were set the limits of nitrates. Overall, the nitrate content ranged from 221 to 334 ppm in spring varieties and from 249 to 384 mg/kg in autumn varieties. Ascorbic acid content was very high in Chinese mustard (Brassica juncea), edible chrysanthemum (Chrysanthemum coronarium) and arugula (Eruca sativa) in both spring and autumn varieties. Values of ascorbic acid ranged from 839 in autumn sowing up to 2909 mg/kg in spring sowing. These non-traditional types of leafy vegetables could be included among the other importants sources of vitamin C in the future.

Senzorska procjena kvalitete napitaka na bazi sirutke

Whey as a by-product of the cheese industry is a source of biological and functional valuable proteins. The aim of this research was to evaluate the commercial potential of whey-based dairy beverages containing a definite amount of semi-skimmed milk addition. The purpose of this paper was to improve the whey flavour via its fermentation by commercial yogurt starter cultures, and via 25 % and 50 % of milk addition. The course of fermentation was monitored by pH and titratable acidity changes. The sensory profile of non-fermented and fermented drinks was assessed using unstructured graphical scales. No significant differences in acidity were found between the samples which were fermented for 3 or 4 hours, but a significant difference was found between samples of whey drinks without milk and samples with milk addition. Fermentation by yoghurt culture did not bring statistically significant improvement of the whey drink organoleptic properties, while the addition of milk was the most important factor influencing not only the total sensory quality of the whey drinks but also their flavour, appearance, colour, viscosity and homogeneity.Sirutka kao nusproizvod industrije sira izvor je biološki i funkcionalno vrijednih proteina. Cilj ovog istraživanja bio je procijeniti komercijalni potencijal napitaka na bazi sirutke koji sadrže određeni dodatak djelomično obranog mlijeka, odnosno poboljšati okus sirutke fermentacijom s komercijalnim jogurtnim starter kulturama, te dodatkom 25 % i 50 % mlijeka. Tijek fermentacije praćen je promjenom pH i titracijske kiselosti. Senzorski profil nefermentiranih i fermentiranih napitaka procijenjen je pomoću nestrukturirane grafičke skale. Nije bilo značajnih razlika u kiselosti između uzoraka koji su fermentirani 3 ili 4 sata, ali je utvrđena značajna razlika između uzoraka sirutke bez i s dodatkom mlijeka. Fermentacija s jogurtnim kulturama nije donijela statistički značajno poboljšanje organoleptičkih svojstava napitaka na bazi sirutke, a dodavanje mlijeka bio je najvažniji čimbenik koji je utjecao ne samo na ukupnu senzorsku kvalitetu sirutkinih napitaka, već i na njihov okus, izgled, boju, viskoznost i homogenost

Comparing the quality of honey from beekeepers and honey from the market chain

Honey is a valuable food for its beneficial nutritional and dietetic effects. The quality of honey fluctuates considerably according to various criteria, the adulteration of honey with cheaper substitutes is not negligible. The quality of honey in the market chain with honey taken from beekeepers was compared in this study. A total of 10 samples from each group were tested for basic qualitative markers and compared with legislative criteria. The samples were analysed for fructose and glucose content, water content, titratable acidity and two tests for illegal sugar additions. The results revealed the addition of 25% of the technical syrup in one sample of honey from the market chain, one sample had the sum of fructose and glucose 56,3%, it is below the required limit 60% (differed by 6,3%). In other parameters the samples complied with the valid legislation. All tested parameters in honey from beekeepers met the criteria of the legislation, only 1 sample of blossom honey had the sum of fructose and glucose just below the required limit. The sum of fructose and glucose in this sample was 58.3 %, it differed by 2.9% from the required content of 60%. Sensory analysis was used to assess four samples of honey from beekeepers collected by different techniques. Results have not shown significant difference in sensory properties between manually pressed honey and honey obtained after whirling. The responses characterizing the favourable sensory properties of the examined honey samples were prevailing. The difference between the perception of honey after whirling and honey harvested by press manually was not demonstrated in sensory properties

The effect of food with different glycaemic index on the blood glucose level

Blood glucose levels are affected by many factors including the type of foods consumed, processing technology and cooking method. Hormone insulin lowers blood glucose to its constant level, while glucagon, growth hormone, adrenalin and glucocorticoids have the opposite effect. High steepness of the blood glucose level rise after meals may be unfavourable for the organism. Sugars are transferred into the blood at different speeds according to the type of food. Therefore the aim of this study was to confirm experimentally the effect of food on blood glucose levels in men and women of different ages. Two types of low, medium and high-glycaemic index (GI) foods were given to 4 men and 4 women of different age (from 35 to 65 years). All volunteers were healthy, slightly overweight, and without any regular sporting activity. None of them had any idea about their daily carbohydrates consumption and what the term glycaemic index meant. The volunteers came to the GI determination fasted in the morning. Their rise in blood glucose level was monitored by glucometer before the meal and after 1 and 2 hours of the consumption of baked potatoes (GI 85), white bread bun (GI 70), boiled potatoes (GI 64), rye bread (GI 62), potato dumplings (GI 52) and white cooked spaghetti (GI 41). Fasting blood sugar levels of volunteers highly depended on their age (p <0.0001) and gender (p <0.0001). The blood glucose values increased with age and were higher in men than in women. Significant influence of food GI on blood glucose levels in both men and women in all the age categories was observed (p <0.0001). An interaction between age and gender was also statistically highly significant (p <0.0001). One hour after consuming food the blood glucose values were significantly different from the values of fasting (p = 0.0035). The differences of these values did not depend on the age (p = 0.0574) and sex (p = 0.8256) of volunteers, but there was a significant difference on the GI value of food (p <0.0001). Significant interactions were also found in case of sex*age (p = 0.0002), age*GI (p <0.0001) and age*sex*GI (p <0.0001). Medium correlation was found between the GI values of food and the rise of blood glucose levels after 1 h (r = 0.6468). After the consumption of high-GI foods the values of glycaemia did not returned to their fasting levels even after 2 hours. There was still significant difference (p = 0.0032), but the values after 2 h were also statistically different from those after 1 hour (p <0.0001). The response to a particular type of consumed food depended on age (p = 0.0018) and especially the GI of foods

The effect of storage on quality of herbs genus Origanum

Herbs of Origanum genus are rich in essential oils and contain large amounts of phenols, lipids, fatty acids, flavonoids and anthocyanins. Antioxidant activity of these herbs depends on many factors, including the type herbs, post-harvest processing and subsequent processing. The aim of this study was therefore to confirm the hypothesis that the composition of oils of these two herbs of the Origanum genus depends on the post-harvest treatment of herbs and that the dried herb antioxidant activity is higher for fresh than that of frozen herbs. Lamiaceae family herbs: oregano (Origanum vulgare L.) and Greek oregano (Origanum heracleoticum L.) were planted and analyzed. Herb samples were extracted by hot demineralised water. DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging method was used for antioxidant activity assessment. The total phenolic content was determined spectrophotometrically by using Folin-Ciocalteu reagent. Steam distillation of essential oils was carried out via Clevenger Apparatus. The obtained essential oils were analysed by GC-MS technique. Results of tested fresh, dried and frozen herbs showed a considerable potential for quenching the free DPPH radical. Significantly higher antioxidant activity was found in dried herbs comparing to fresh and frozen, but only in case of values calculated per 100 g of the sample. However, the differences were not statistically significant after recalculation when expressed on dry matter content. There was no difference between fresh and frozen samples. The content of total phenols was significantly higher in dried than in frozen herbs in values recalculated per 100 g of sample. A strong correlation between the results of DPPH and TPC was found again only for values expressed per 100 g of the sample. Post-harvest treatment of herbs affects the composition of their essential oils. The dominant essential oil component of Greek oregano is carvacrol with a proportion of 60% or more. On the contrary, there is no such dominating component in oregano essential oil but there are more components with a share of 10 to 20%

The effect of drying on antioxidant activity of selected lamiaceae herbs

Antioxidant activity and total phenolics content of selected fresh and dried herbs from the Lamiaceae family were compared. The analysed herbs included Thymus vulgaris, Origanum vulgare, Satureja hortensis, Origanum majorana, and Origanum heracleoticum from the 1st and the 2nd harvests. The antioxidant activity was determined using DPPH method and the total content of phenols was analysed using the Folin-Ciocalteu reagent. Ascorbic and gallic acids were used as reference standards. All the analysed herbs had the reasonable potential to reduce the DPPH radical. The dried herbs from the 2nd harvest had the highest antioxidant activity. Oregano exhibited the highest antioxidant activity from the analyzed samples of both harvests together. The descending order of the samples was oregano ˃ Greek oregano ˃ marjoram ˃ summer savory ˃ thyme. Marjoram from the 2nd harvest had the highest antioxidant activity from the fresh samples. The lowest activity was observed in thyme from the 2nd harvest. In case of dried samples, the highest antioxidant activity was measured in sample of Greek oregano from the 2nd harwest. The lowest activity was observed in thyme from the 1st and 2nd harvest again. The descending order of total phenolics content for both harvests together was oregano ˃ Greek oregano ˃ marjoram ˃ summer savory ˃ thyme. In case of fresh herbs the highest total phenolics content was measured in oregano from the 1st harvest, the lowest content was measured in summer savory from the 2nd harvest. Greek oregano from the 2nd harvest had the highest values from dried herbs. Dried thyme from the second harvest had the lowest total phenolics content. The correlation between the DPPH values and the total content of phenols was determined (for fresh herbs: 0.4917; for dried herbs: 0.8698). According to the total content of phenols a statistically significant difference between the fresh and dried herbs from the 2nd harvest (p = 0.0185) was found

Nutritional values of edible Coleoptera (Tenebrio molitor, Zophobas morio and Alphitobius diaperinus) reared in the Czech Republic

Edible insects have gained the status of highly nutritious food with high protein and fat content. However, nutritional value of insects is not constant. It could be affected by species, developmental stage, rearing technology, nutrition or sex. This study's goal is to determine the protein and fat contents of three edible beetle species (giant mealworm - larvae of Zophobas morio, mealworm - larvae of Tenebrio molitor and, lesser mealworm - larvae of Alphitobius diaperinus) bred in the Czech Republic. Based on the obtained results, all investigated species could be considered as a reasonable source of lipids and two of them (mealworm and lesser mealworm) are also an excellent source of protein. Crude protein content of mealworm (630 g. kg-1 DM) was found to be higher than in other studies. The investigated species of lesser mealworm contained 600 g of crude protein/kg DM, which was equal to the results of other authors. Most authors report a higher content of nitrogen in the giant mealworm than were the values measured by this experiment (390 g.kg-1 DM). The lipid content in the tested samples was found in a range of 170 - 390 g.kg-1 DM. The highest lipid content was found in the larvae of giant mealworm and the lowest lipid content was found in the larvae of mealworm. The determined fat content of lesser mealworms was 290 g.kg-1. The fatty acid profiles of all samples were also determined. © 2016 Potravinarstvo. All rights reserved

Comparison of the carbohydrate content in apples and carrots grown in organic and integrated farming systems

The aim of this study was to compare some quality parameters of apples and carrots from organic and integrated farming systems. In addition, the cultivars of carrots were grown in two plant densities (600 or 900 thousand plants per hectare). The fructose, glucose, saccharose and dry matter content of seven apple cultivars (Florina, Zvonkové, Topaz, Šampion, Ontario, Melrose and Idared) and two carrot cultivars (Afalon F1 and Cortina F1) were analysed by HPLC and gravimetric methods, respectively. Significant differences were found between organic and integrated apple samples. The interactions between cultivars and farming methods were also significant (p <0.0001). The dry matter and sugar level tendencies were not the same for all apple cultivars. Conversely, more consistent data were obtained for the two carrot cultivars. The bio carrots of both cultivars showed significantly lower dry matter content (p = 0.0004) and higher carbohydrate content (pfructose = 0.0303, pglucose = 0.0003, psucrose = 0.0083) than the samples from integrated production. Other factors like cultivar and plant density also played an important role in sugar content in carrots. Different densities of plants significantly affected the glucose content (p = 0.0373). Cultivar Aftalon F1 showed higher concentration of monosaccharides compared to Cortina F1 (pfructose = 0.0001 and pglucose <0.0001)

Osnovni sastav mlijeka i slobodne masne kiseline kao parametar lipolize mlijeka holstein krava

The aim of this study was to evaluate in detail the relationship between the basic milk components (fat and protein percentage) and the free fatty acids (FFA) content, as indicators of spontaneous and/or induced lipolysis. The additional aim of the study was to compare the FFA content of milk with respect to spontaneous and induced lipolysis. Milking was carried out in herringbone parlour twice a day. In total, 540 milk samples were obtained for evaluation of spontaneous (n=240) and induced lipolysis (n=300). The milk samples for determination of basic milk components and FFA (li¬polysis) levels were collected during four subsequent lactation weeks. Milk samples for spontaneous lipolysis detection were taken directly in parlour immediately after milking using the ICAR methodology and subsequently grouped. Induced lipolysis was observed from bulk milk in time 0, 1, 2, 3, and 4 hours after milking (T0-T4). The evaluation of basic components and FFA content was carried on MILKOSCAN F120 (Foss Electronic; Denmark). Statistical evaluation was carried out using SAS 9.3. (SAS/STAT® 9.3, 2011). An increase of one percentage of milk fat was equal to 0.318 mmol x 100 g-1 FFA decline (spontaneous lipolysis) or from 0.232 to 0.370 mmol x 100 g-1 FFA decline (induced lipolysis T0-T4) respectively. One percentage increase of milk protein was equal to 1.219 mmol x 100 g-1 FFA increase (spontaneous lipolysis) or 0.421 to 1.531 mmol x 100 g-1 FFA decrease (induced lipolysis T0 - T4) respectively. Significant differences (P<0.01) were detected among FFA content in relation to spontaneous and induced lipolysis evaluated during storage and cooling after milking. The minimal differences were detected between the FFA content during 4 hours cooling and storage of milk in the tank.Cilj istraživanja bio je detaljno ispitati odnose između osnovnih sastojaka mlijeka (udjela masti i proteina) i sastava slobodnih masnih kiselina (SMK), kao pokazatelja spontane i/ili inducirane lipolize. Dodatni cilj bio je usporediti sastav SMK mlijeka s obzirom na spontane i inducirane lipolize. Mužnja je provedena u izmuzištu tipa riblja kost dva puta dnevno. Analizirano je 540 uzoraka mlijeka, od čega za ocjenu spontane (n=240) i inducirane (n =300) lipolize. Prikupljeni su uzorci mlijeka za određivanje osnovnih sastojaka mlijeka i SMK (lipoliza) tijekom četiri uzastopna tjedna mužnje. Uzorci mlijeka za otkrivanje spontane lipolize uzeti su izravno u izmuzištu odmah nakon mužnje korištenjem ICAR metoda i nakon toga su grupirani. Inducirana lipoliza uočena je u uzorcima mlijeka u vremenu 0, 1, 2, 3, i 4 sata nakon mužnje (T0-T4). Procjena osnovnih sastojaka mlijeka i sadržaja SMK utvrđena je pomoću MILKOSCAN F120 (Foss Electronic; Denmark). Statistička analiza provedena je korištenjem programa SAS 9.3. (SAS/STAT® 9.3, 2011). Utvrđeno je da je povećanje udjela mliječne masti za 1 % jednako smanjenju SMK od 0,318 mmol x 100 g-1 (spontana lipoliza) ili smanjenju SMK od 0,232- 0,370 mmol x 100 g-1 (inducirana lipoliza T0-T4). Povećanje udjela proteina za 1 % jednako je porastu SMK od 1,219 mmol x 100 g-1 (spontana lipoliza) ili smanjenju SMK od 0,421-1,531 mmol x 100 g-1 (inducirana lipoliza T0-T4). Utvrđene su značajne razlike (P<0,01) između sadržaja SMK u odnosu na spontane i inducirane lipolize tijekom skladištenja i hlađenja mlijeka nakon mužnje. Minimalne razlike utvrđene su između sadržaja SMK tijekom 4 sata hlađenja i skladištenja mlijeka u spremniku