Linear concentrating collector as an air heater in the heating system of building in Polish climatic conditions

The article presents the analysis of the performance of a concentrating collector in the heating system of a residential building. Air was used as the working fluid. The heating requirements of the building were determined for each day of the year. The amount of direct irradiation reaching the absorber’s surface on all the days of the year was determined with the use of hourly meteorological data for Wroclaw, shared by the Ministry of Infrastructure and Growth. It was assumed that the collector is equipped with a tracking system working in one axis. Calculations and comparisons were made for the amount of solar irradiation for three values of the receiver’s inclination angle: β1=60°, β2=90° and β3=30°. Statistical method was used in order to determine the optimum inclination of the mirror and the amount of flowing air. This method involves creating a plan of experiment with three levels of changeability for two input factors. In the last stage, the amount of heat obtained from the installation during all the days of the year was analysed. The gains were juxtaposed on the diagram with the building’s heat demand. The analysis has shown that the heat requirements can be met only partially

The acrylamide content in some potato products depending on the raw material

Celem pracy było określenie wpływu dwóch odmian ziemniaka użytych do sporządzenia frytek, kostki ziemniaczanej i suszu z ziemniaka gotowanego (puree) na zawartość akrylamidu w gotowych produktach. Stwierdzono, że ziemniaki badanych odmian charakteryzowały się odpowiednim składem chemicznym bulw, wymaganym przy produkcji frytek oraz kostki ziemniaczanej i suszu przeznaczonego na puree. Zawartość akrylamidu w przetworach ziemniaczanych zależała od użytej odmiany ziemniaka i związanej z nią zawartością cukrów redukujących w bulwie. Z ziemniaków odmiany Innovator o niższej zawartości cukrów redukujących w bulwie, otrzymano puree o około 36% niższym poziomie akrylamidu, kostkę ziemniaczaną o około 29% i frytki o około 15% mniejszej ilości tego związku, w porównaniu z produktami otrzymanymi z ziemniaków odmiany Santana. Niezależnie od zastosowanej w badaniach odmiany ziemniaka, najniższą zawartością akrylamidu charakteryzowały się frytki (349µg·kg-1), a najwyższą susz z ziemniaka gotowanego — puree (1156µg·kg-1).The aim of this study was to determine the effect of two potato varieties used in the preparation of French fries, dehydrated potato dice and dehydrated potato (puree) on the acrylamide content in ready product. It was stated that potato tubers of two varieties were of suitable chemical composition, which is required for the production of French fries, dehydrated potato dice and puree. The acrylamide content in processed potato products depended on the used potato variety and the related reducing sugars content in its tubers. Puree prepared from tubers of potato variety Innovator with a lower content of reducing sugars contained 36% lower levels of acrylamide, dehydrated potato — 29% and French fries — 15% less of this compound in comparison with products obtained from potato of variety Santana. Regardless of the potato variety which was used in the study, the lowest acrylamide content was in French fries (349μg·kg-1) and the highest in puree (1156μg·kg-1)

Modeling of Antioxidant Activity, Polyphenols and Macronutrients Content of Bee Pollen Applying Solid-State 13C NMR Spectra

An application of solid 13C nuclear magnetic resonance (NMR) spectroscopy for the determination of macronutrients, total polyphenols content, antioxidant activity, N C S elements, and pH in commercially available bee pollens is reported herein. Solid-state 13C NMR spectra were recorded for homogenized pollen granules without chemical treatment or dissolution of samples. By combining spectral data with the results of reference analyses, partial least squares models were constructed and validated separately for each of the studied parameters. To characterize and compare the models’ quality, the relative standard errors of prediction (RSEP) were calculated for calibration and validation sets. In the case of the analysis of protein, fat and reducing sugars, these errors were in the 1.8–2.5% range. Modeling the elemental composition of bee pollen on the basis of 13C NMR spectra resulted in RSEPcal/RSEPval values of 0.3/0.6% for the sum of NHCS elements, 0.3/0.4% for C, 1.8/1.9% for N, and 4.2/6.1% for S quantification. Analyses of total phenolics and ABTS antioxidant activity resulted in RSEP values in the 2.7–3.5% and 2.8–3.8% ranges, respectively, whereas they were 1.4–2.1% for pH. The obtained results demonstrate the usefulness of 13C solid-state NMR spectroscopy for direct determination of various important physiochemical parameters of bee pollen

The Free-Amino-Acid Content in Six Potatoes Cultivars through Storage

Potatoes of six cultivars (Solanum tuberosum L.) with red, purple, and yellow flesh were stored at 2 and 5 °C for 3 and 6 months, and the influence of these factors on the content of free amino acids was determined. The potato cultivar and storage time had the greatest impact on the free amino acid content. The tubers of red-fleshed (Rote Emma) and purple-fleshed (Blue Congo) potatoes contained over 28 mg/g DM of free amino acids, and the Blaue Annelise cultivar with purple flesh had over 18 mg/g DM. After 6 months, the highest increase in their content (by 36%) was recorded in tubers of the Fresco cultivar (yellow-fleshed). In the analysed potatoes, the content of alanine, proline, serine, γ-aminobutyric acid, and α-aminoadipic acid increased, while that of asparagine, aspartic acid, and glutamine decreased. Asparagine decreased to the greatest extent in “Blaue Annelise” potatoes (by 24%) and that of glutamine in tubers of Rote Emma and Vineta by 18%

Comparative Evaluation of the Antioxidative and Antimicrobial Nutritive Properties and Potential Bioaccessibility of Plant Seeds and Algae Rich in Protein and Polyphenolic Compounds

Spice plants are not only a source of nutrition compounds but also supply secondary plant metabolites, such as polyphenols. Therefore, their bioaccessibility is an important issue. In order to understand the biological activity of polyphenols present in spice plants, it is necessary to broaden knowledge about the factors influencing their bioaccessibility, including nutritional factors. Therefore, the objective of this research was to determine the antioxidative and antimicrobial nutritive properties and potential bioaccessibility of plant seeds and microalgae rich in protein and polyphenolic compounds. Plant seeds rich in protein—i.e., black cumin, milk thistle, fenugreek, almonds, white sesame, white mustard, eggfruit and the two most popular algae, chlorella and spirulina—were analyzed for total polyphenolic compounds (TPC) and antioxidant properties (ABTS, FRAP), as well as their potential bioaccessibility, antimicrobial activity, basic chemical composition and amino acid profiles. With regard to the TPC, the highest levels were found in star anise, followed by milk thistle, white mustard and fenugreek, whereas the lowest were noted in white sesame, almonds, eggfruit, spirulina and chlorella. White mustard and milk thistle showed the highest antioxidant capacities and almonds, eggfruit, spirulina, and chlorella the lowest according to the ABTS and FRAP assays. The widest spectrum of microbial growth inhibition was detected for fenugreek extract, which showed antimicrobial activity against four analyzed microorganisms: B. subtilis, P. mirabilis, V. harveyi and C. albicans. The protein from seeds of black cumin, milk thistle, white mustard and eggfruit and chlorella was not limited by any essential amino acids. Among all analyzed plants, fenugreek seeds were judged to have potential for use in food formulation operations in view of their antioxidant activity and amino acid profile. Based on the results, intake of polyphenols together with protein in plant seeds does not have a major impact on the potential bioaccessibility of a range of polyphenols and phenolic metabolites

Stability monitoring of biological active compounds in juice obtained from blue-fleshed potatoes

In recent years, more and more raw materials and food products with high organoleptic and nutritional values have been brought on the market, such as potatoes with purple and red flesh. They are characterized, above all, by an attractive colour but also by a very good taste, flavour, and higher nutritional value than traditional, light-fleshed tubers. In addition, the higher content of polyphenol compounds, especially anthocyanins in the coloured tubers, which has beneficial effects on the human body, should be noted. The aim of the work was to determine the influence of temperature and pH on the stability of biological active compounds from blue-fleshed potato. The material used for a study were purple-fleshed potatoes and juice made from the chosen potatoes. In tubers determined primary chemical composition, total phenolic content, antioxidant activity, anthocyanins. The juice obtained from the selected tubers was subjected to pH ranging from 1 to 11 and the temperature of 60 ° C, 70 ° C, 80 ° C, 90 ° C, 100 ° C for 10 minutes. In juice was determined total phenolic content and antioxidant activity. [...]Agronomijos fakultetasVytauto Didžiojo universiteta

Effect of Acetylation on Physicochemical and Functional Properties of Commercial Pumpkin Protein Concentrate

The purpose of the present study was to determine the effects of acetylation with different doses of acetic anhydride on the chemical composition and chosen functional properties of commercial pumpkin protein concentrate (PPC). The total protein content decreased as compared to unmodified samples. Electrophoretic analysis revealed that in the acetylated pumpkin protein, the content of the heaviest protein (35 kDa) decreased in line with increasing concentrations of modifying reagent. Acetylation of PPC caused a significant increase in water-binding and oil-absorption capacity and for emulsifying properties even at the dose of 0.4 mL/g. Additionally, an increase in foaming capacity was demonstrated for preparations obtained with 2.0 mL/g of acetic anhydride, whereas acetylation with 0.4 and 1.0 mL/g caused a decrease in protein solubility as compared to native PPC

“HydroSOStainable” Concept: How Does Information Influence Consumer Expectations towards Roasted Almonds?

17 páginas.- 3 figuras.- 5 tablas.- 52 referencias.-Water scarcity is one of the top five key global risks over the last years, and agriculture is the major and least efficient user of fresh water. In this scenario, the “hydroSOStainable” concept has been developed and registered to protect fruits and vegetables cultivated with a volume of water below the crop evapotranspiration. The purpose of this experimental study was to investigate how the information influence the consumer liking and preference of the roasting almonds labelled as “hydroSOStainable” and “conventional”, although belonged to the same sample. Thus, we explored 300 consumers (Seville, Spain (high levels of water stress) versus Donostia, Spain and Wroclaw, Poland (regions with no water stress)) preference and acceptance of roasted almonds using satisfaction degree, CATA and willingness to pay questions. The present study demonstrated that both location and sociodemographic aspects influenced consumers perception and liking. Consumers living in areas with water restrictions were more susceptible to be influenced by the hydroSOStainable/conventional concept, while consumers from regions without water restrictions would need more information to choose a sustainable product. Both man and women, centennials and millennials scored higher the supposed hydroSOStainable almonds, while generation X was not really influenced by the information effect. Finally, 77% of consumers, regardless of location, were willing to pay a higher price for the almonds labelled “hydroSOStainable”. Consequently, these results provide valuable information for the government and food industry about consumer choice regarding sustainable products, depending on the location, knowledge, and sociodemographic aspects.The study has been funded by the Spanish Government (Ministerio de Ciencia e Innovación, (MCI), Agencia Estatal de Investigación (AEI)), through a coordinated research project, including (i) Universidad Miguel Hernández de Elche (AGL2016-75794-C4-1-R, Productos hidroSOStenibles: identificación de debilidades y fortalezas, optimización del procesado, creación de marca propia, y estudio de su aceptación en el mercado europeo, hydroSOS foods) and (ii) Universidad de Sevilla (AGL2016-75794-C4-4-R). These projects have been also funded by Fondo Europeo de Desarrollo Regional (FEDER) “Una manera de hacer Europa”, (MCI/AEI/FEDER, UE).Peer reviewe

Effect of Aging Vessel (Clay-Tinaja versus Oak Barrel) on the Volatile Composition, Descriptive Sensory Profile, and Consumer Acceptance of Red Wine

13 páginas.- 2 ilustraciones.- 3 tablas.- 23 referenciasConsumers look for unique wines, offering pleasant experiences. Wine producers need to open new markets and are targeting countries with fewer traditions in drinking red and complex wines, such as Poland, Russia and Germany. The use of less popular aging vessels (e.g., clay-tinajas) will help in creating unique wines. The aim of this study was to evaluate the effect of the aging vessel on the volatile and sensory profiles and consumer acceptance of red wine in Spain and Poland (model of potential new markets). Three wines were studied: (i) wine A, aged in a clay-tinaja with non-permeable coating); (ii) wine B, aged in clay-tinaja without coating; and (iii) wine C, aged in oak barrels (control). The key families in the volatile profiles were esters (wines B and C) and organic acids and terpenes (wine A). Wine A was described as sour and bitter, wine B had a distinctive mineral note, and wine C had a complex profile with typical wood notes. Finally, wines C and A were the preferred ones for Spanish and Polish consumers, respectively. Clay-tinaja wine A can be a good option to introduce clay-tinaja wines in Polish and similar markets because it is a unique product and fulfills the sensory demands/habits of Polish consumers.This research has been financed through an Innovation Project (Valorización de materiales tradicionales para vinificación de vinos de calidad, GOVALMAVIN, file number 20180020012104) 80% co-financed by the European Agricultural Fund for Rural Development (EAFRD) of the European Union and 20% by the Spanish Ministry of Agriculture, Fisheries and Food, within the framework of the National Program for Rural Development 2014–2020.Peer reviewe

Impact of deficit irrigation on fruit yield and lipid profile of terraced avocado orchards

International audienceAvocado (Persea americana Mill.) is a subtropical tree, particularly sensitive to either an excess or a lack of water. Understanding this balance is crucial to determine the optimum water supply and enhance crop productivity. The rising shortage of water resources in semiarid producing regions and the need for irrigation optimization call for sustainable water savings. A 3-year monitoring study with avocado cv. “Hass” tested sustained-deficit irrigation strategies supplying 33, 50 or 75% of the estimated crop water demand. They were compared with a control strategy supplying 100% of the estimated crop water demand. The leaf water potential, stomatal conductance, tree growth, yield and several fruit quality parameters were evaluated. The yield, tree growth and fruit size were significantly and proportionally lessened by deficit irrigation treatments. Over the study, the average yields amounted to 31.6, 38.3 and 43.8 kg tree−1 in the 33, 50 and 75% treatments respectively, which were significantly less than the yield of 47.5 kg tree−1 measured in the control. The 33% and 75% sustained-deficit irrigation treatments increased the omega 3 and omega 6 fatty acids as well as the unsaturated fatty acids (oleic); however, the 33% deficit irrigation treatment significantly reduced the yield, size and fruit weight. We consider, therefore, that approximately 25% of the irrigation water can be saved without adversely affecting the avocado tree performance in short and medium terms and we recommend implementing the 75% sustained-deficit irrigation strategy. Here we show for the first time the key role of redesigning irrigation strategies in Mediterranean areas, focusing on the benefits of sustained-deficit irrigation, which can save water, encourage water use efficiency and enhance fruit quality. In order to save water, it is critical and necessary to implement such novel water shortage strategies, at the affordable cost of reducing fruit yield while enhancing its quality