Volumen 31 (2014): Heft 1 (June 2014)

Celiac disease is a permanent enteropathy caused by the ingestion of gluten, a protein occurring in wheat, rye, and barley. Gluten-free products often have a shorter shelf life, lower quality, and not so pronounced flavour. Therefore, it is necessary to develop new gluten-free products with higher quality and pronounced taste. The aim of this study was to investigate the influence of soy flour on the yellow maize-amaranth dough rheological properties and bread quality. To determine the influence of soy flour on gluten-free dough rheological properties and bread quality, soy flour was added at 45%, 50% and 60% to yellow maize flour basis. To study the effect of the amount of water used in the recipe on dough rheological properties and bread quality, each sample (n=7) was prepared in two versions: one with the dough yield 196, and the other with the dough yield 252. The main quality parameters of dough and bread were determined using the following methods: the firmness and resilience of dough, as well as the hardness of bread slice – with a TA.XT.plus Texture Analyser; moisture content of dough – with a thermostat; moisture content of bread crumb – with a Precisa XM 120 at the temperature of 110 °C; and color of bread crumb – in the CIE L*a*b* color system using a ColorTec-PCM/PSM. The best results of dough rheological properties were obtained for samples with dough yield 196, but the best quality of bread – for samples with dough yield 252. It was proved that soy flour improves not only the dough firmness and resilience but also the volume, texture, hardness, moisture content and color of gluten-free bread. No significant differences in the influence of soy flour on dough rheological properties and bread quality were found between the samples with various added amounts of soy flour (45%, 50%, or 60%).

The aim of the study was to evaluate the effect of freezing, thickening and storage on the physical properties of the strawberry desserts made with addition of various hydrocolloids. The strawberry cultivars ‘Polka’, ‘Honeoye’, and ‘Senga Sengana’ harvested in Latvia were used in the study. The strawberries were processed in a blender for obtaining a homogenous mass. The strawberry mass was analyzed fresh and after storage at -18 °C. Both fresh and frozen strawberry mass samples with added gelatine, xanthan gum, and sodium carboxymethyl cellulose were whisked until obtaining dessert. For determination of the optimum hydrocolloid amount, sensory evaluation was done using a five-point hedonic scale. Moisture, soluble solids content, density, and pH of the product were determined. Apparent viscosity was measured using a rotational viscometer DV–III Ultra. Consistency of the dessert during its storage was evaluated using a texture analyser TA.XT.plus. The results of sensory evaluation allow concluding that in order to provide the most acceptable consistency, colour, and taste of strawberry dessert, the optimum quantity of carboxymethyl cellulose and xanthan gum to be added is 0.6% and that of gelatine is 6%. During freezing, the soluble solids content and pH level decreased in the strawberry mass, whereas the addition of hydrocolloids increased these values. The moisture content in strawberry puree, in its turn, as a result of freezing increased under the influence of syneresis, but added hydrocolloids, on the contrary, decreased this influence. Also the viscosity and consistency of the strawberry puree prepared from the researched cultivars decreased under the influence of freezing, whereas the addition of hydrocolloids increased both the values, making the strawberry dessert firmer. The research suggests that strawberry dessert with gelatine had the most pronounced changes during storage, but strawberry dessert with added xanthan gum and carboxymethyl cellulose changed the least.

This study was done to evaluate the number of gastric mucoid epitheliocytes and parietal cells in relation to the amount of helicobacteria in the fundic gland region of 30 domestic dogs (Canis familiaris) Gastric mucosa samples were taken from the fundic gland region in eight strictly determined places to detect helicobacteria in 10 microscopic visual fields by histological examination, to find out the quantity of helicobacteria at the superficial epithelium, in gastric pits, and in fundic glands by classifying it as absent, mild, moderate, and severe, as well as to evaluate the number of mucoid epitheliocytes of the gastric superficial–pit epithelium and of the parietal cells of fundic glands. Out of all examined 2400 microscopic visual fields, mild and moderate amounts of helicobacteria localizing mainly at the superficial epithelium and in gastric pits were detected in 69.0–77.5% of cases, and only in around 20% of cases they were found in different amounts deeper into the fundic glands. The number of mucoid epitheliocytes (199±20 cells in one visual field) was only slightly larger in places with a severe amount of helicobacteria compared to places with no helicobacteria (195±16 mucoid epitheliocytes in one visual field). Also the number of parietal cells in the fundic glands did not differ markedly among the places with different amounts of helicobacteria; however, in places with a severe amount of helicobacteria, parietal cell count tended to decrease to 76±8 cells in one visual field, but in places free from helicobacteria there were 83±9 parietal cells in one visual field.

Polyphenol compounds are very important components of cider – they are responsible for the colour and the bitterness and astringency balance of cider. The polyphenolic profile of apples and apple drinks is influenced by several factors: apple variety, climate, maturity, and technological processes applied. This research paper concerns the influence of apple variety on the phenolic compounds and sensory properties of cider. Fermentation of 12 varieties of apple juice with Saccharomyces cerevisiae yeast ‘71B-1122’ (Lalvin, Canada) was performed in a laboratory of the Faculty of Food Technology of the Latvia University of Agriculture. The total phenol content (TPC) was determined according to the Folin-Ciocalteu spectrophotometric method. Individual phenolic compounds were analysed using HPLC. Sensory properties (clarity, the apple, fruit and yeast aroma, the apple and yeast taste, sourness, astringency, and bitterness) were evaluated by trained panelists using a line scale. Special attention was paid to the use of dessert apples for the production of cider. The most important sensory properties of cider are the aroma and taste of apples and fruit. All cider samples showed the intensity of apple aroma ranging from 5.3 to 7.6 points, and higher results were obtained for cider from the bvariety ‘Auksis’ apples. The TPC in cider samples varied from 792.68 to 3399.78 mg L^-1: Among crab apples, the highest TPC was detected in ciders made from the ‘Hyslop’ and ’Riku’ varieties, whereas among dessert apples, the highest TPC was detected in ciders made from the ‘Antonovka’ variety. Among the twelve phenols identified in cider samples, chlorogenic acid and caffeic acid were the dominating ones. Variation in the sensory properties of ciders was dependent on the physicochemical composition of the apples used.

Raw milk is an ideal growth medium for microorganisms (including many fungal species), as such milk provides all necessary nutrients and conditions for their growth. The objective of the present study was to investigate the diversity of microscopic fungi in the milk obtained in Latvian organic farms depending on cow herd size and season. The study was carried out on 547 milk samples taken from 14 organic dairy farms from December 2011 to November 2012. The farms were divided into three groups according to herd size: small (S - 3-30 cows per shed), medium (M – 31–60 cows per shed), and large (L – 61–120 cows per shed). Milk samples from all four quarters in the same sampling tube were studied. Yeasts and moulds were found in 63.1% and 44.2% of samples, respectively. The identified mould strains belonged to 15 genera - most frequently to Absidia, Aspergillus, Apophysomyces, Mucor, Penicillium, and Rhizopus spp. The highest occurrence of yeasts and moulds was in L herds (73.6% and 50.9%, respectively). Also, milk samples from L herds had the greatest degree of yeast and mould contamination (5.3 and 2.8 log CFU mL^-1, respectively). It was found that the occurrence of yeasts was similar by seasons (54.9–68.9%), varying from 5.5 log CFU mL^-1 in winter to 2.1–3.3 log CFU mL^-1 in other seasons. The occurrence of moulds was the highest in spring (61.6%) and autumn (58.5%), but in winter and summer it was twice lower. The milk samples obtained in winter and summer contained more mould colonies (2.7 and 2.5 log CFU mL^-1, respectively) than those obtained in spring and autumn (1.8–1.3 log CFU mL^-1, respectively).