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Laetiporus sulphureus (chicken of the woods) is a wood decaying mushroom with positive medicinal and biological effects. The aim of this study was to determine its chemical composition including the main organic components (protein, fat, fibre, and ash contents, different protein fractions, the free amino acid level, soluble oligo- and polysaccharides, phenolics), the in vitro digestibility, the free radical scavenging activity, and twenty mineral elements.Our data demonstrate the characteristic in general valuable chemical composition of the mushroom Laetiporus sulphureus. Protein content in fruiting bodies is not too high (10.6% d.m.), but the biological value (in vitro digestibility, rate of protein fractions, free amino acid content, etc.) is good (including fat and energy levels). Occurrence of “bioactive” components (phenolics, soluble oligo- and polysaccharides) and the measured free radical scavenging activity are similar to these parameters in Pleurotus (oyster) species. Potassium and phosphorus contents are remarkable (28 940 mg kg−1 d.m. and 4890 mg kg−1 d.m., respectively); levels of some poisonous microelements (As, Cd, Cr) are very low or undetectable. Chicken of the woods (Laetiporus sulphureus) is not only a suitable species for human consumption, but can be a new cultivable mushroom of valuable bioactive substances.

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The application of gibberellic acid (GA3), ascorbic acid (ASA) and olive mill wastewater (OMW) as spray was used as possible techniques for storage life prolongation and quality maintenance of bean (Phaseolus vulgaris L.) fruits at 20 and 5 °C. Control and OMW-treated beans displayed greater rates of O2 depletion and CO2 production. GA3-sprayed beans respired slower and revealed the lowest weight losses. Changes in glucose and fructose contents were less inhibited, while higher decrease under OMW treatment was recorded at both temperatures; total protein content profile did not change upon treatments. GA3 and ASA seem to be particularly effective in inhibiting enzymatic browning of beans. GA3 and ASA reduced the metabolic activity of moulds, while inducing the growth of yeasts as compared to the control. OMW-treated beans showed enhanced development of moulds and yeasts. The beneficial effect of GA3 on bean shelf-life prolongation was shown; while the protective effect of ASA was only partial.

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A feeding experiment was conducted on northern pike, Esox lucius L. (123.6±33.3 g initial body weight) applying graded dietary fish oil supplementation resulting three dietary fat levels (without supplementation: 6.2% fat and 11.7, 17.4% fat levels with supplementations) in a recirculation system. Feed consumption, feed efficiency and protein utilization of pike was not affected by the treatment. Whole body lipid content analysis showed that the composition of pike was significantly affected by the increasing level of fish oil supplementation, although no relationship was detected between the dietary and the fillet lipid content, as well as the protein content of fish bodies. High docosahexaenoic acid (DHA, C22:6n-3) proportions were found in the muscle lipids (groups fed fish oil supplementation), as compared to the dietary fatty acid compositions suggesting that with dietary fish oil supplementation the dietary precursors (mainly EPA) enable pike to convert long chain highly unsaturated fatty acids, especially DHA; resulting high DHA: EPA ratios in the fillet.

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Acta Alimentaria
Authors: J. Tarek-Tilistyák, J. Agócs, M. Lukács, M. Dobró-Tóth, M. Juhász-Román, Z. Dinya, J. Jekő, and E. Máthé

The nutritive value, the microbiological safety of oilseed cake (OSC) obtained from naked pumpkin seed (PuC), sunflower seed (SC), yellow linseed (LC), and walnut (WnC), and their impact on wheat flour (WF) dough and bread sensory characteristics at 5% and 10% addition ratio were investigated. The OSCs had high protein (34–50%), fat (8–15%), total dietary fibre (23–36%) content and high energy value (383–444 kcal/100 g)). The OSC samples with a minimal exception fulfilled the requirements of feed legislation in force. An increased water absorption, dough development time, and reduced elasticity were observed probably due to the enhanced fiber and protein content. Dough stability increased with WnC, and decreased with PuC or SC addition. Enrichment provided the appearance of a brown bread for WnC, of a half-brown bread for LC. PuC gave an unusual look. The appearance of OSC fortified bread similar to daily bread, was an advantage resulting the 1st rank for 10% WnC bread and the 2nd one for 10% LC bread (P=0.05). The studied OSCs are suitable for food enrichment, however, in case of PuC and SC fortified flour blends, hydrocolloid application is recommended. Our data suggest that the newly developed fortified breads could be a valuable source for healthy nutrition.

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The aim of this study was to compare efficiency of RP-HPLC (Reversed-Phase High-Performance Liquid Chromatography) and LOC (Lab-on-Chip) methods for wheat gluten protein quantification regarding clustering of wheat cultivars according to the genetic similarity (HMW-GS combinations), as well as to explore relations of these two methods to wheat quality parameters. For that purpose, wheat quality parameters (protein content, falling number, wet gluten content, gluten index, Farinograph, Extensograph, and Amylograph), as well as amounts of gliadin and glutenin fractions by RP-HPLC and LOC methods were determined in two different sets of wheat cultivars (Croatian and Serbian). The percentages of gluten proteins and the values of quality parameters were used to characterize the samples by principal component analysis (PCA). Gluten protein quantification performed by method based on the protein fraction separation by molecular weights (LOC) was better for grouping of genetically similar wheat cultivars than quantification of proteins separated by their different solubility in specified solvent gradient (RP-HPLC). LOC method showed higher potential in wheat quality prediction.

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Proximate composition and physical parameters in nine quinoa cultivars were determined in order to establish differences among them and to contribute to their characterization. Faro, Pichaman, and Baer varieties cultivars were used. The aim of this research was to evaluate the physical and chemical properties and to characterize the protein fractions. All analysed properties showed significant differences between the cultivars. The physical measurements (weight, shape, size, and density) could be used for improving the technology associated with conditioning, transport, and storage of the grain. The protein content ranged from 15 to 18%, fat 6 to 8%, carbohydrates 70 to 74%, and ash from 3.5 to 4.4%, showing an outstanding nutritional profile. The relative quantity of soluble proteins (albumins and globulins) ranged from 40 to 65%, except in Faro variety cultivar, which presented 16%. The relative percentage of insoluble protein (prolamins and glutelins) ranged from 25 to 34%. The obtained information in this research could be useful in determining seed-quality, automating production, improving cultivation practices and technologies, and developing food products with enhanced nutritional qualities.

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The primary purpose of these researches was to optimize single-cell protein (SCP) production process using Saccharomyces cerevisiae NCAIM Y.00200 and Kluyveromyces marxianus DSM 4908 strain, and then to analyse the changes in yield of single-cell protein final product using vitamin supplementation. To determine these values, the total sugar content of the fermentation medium, and the protein content of the yeast was determined. During our work, a particular attention was paid to the change of sugar content and yeast protein quantity. Besides, yield (Yx/s) values, typical of the whole fermentation, were also measured. Protein yield, as the final product of fermentation, featured the efficiency of our work. The results of our optimized trial settings that were considered as control, using S. cerevisiae NCAIM Y.00200 and K. marxianus DSM 4908 strains, were compared with the results of vitamin-supplemented fermentation processes. On this basis, we can say that during our trials vitamin supplementation did not influence the final product yield of processes. The counted protein yields during fermentation were between 0.4–0.7 g g−1.

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Acta Alimentaria
Authors: N. Parunović, M. Petrović, V. Matekalo-Sverak, D. Radojković, D. Vranić, and Č. Radović

The objective of this paper is to investigate variability in chemical composition, total fatty acid and cholesterol content in m. longissimus dorsi (MLD) of Mangalitsa, swallow-belly (LM) and white (BM), and Swedish Landrace pigs (SL). Compared to SL, the total fat content has been 14.2% higher in BM, while it has been 10.2% higher in LM. SL fatteners contained significantly less cholesterol in MLD compared to LM and BM (−13.6 and −14.8%, P≤0.05). A higher percentage of SFA (+8.5 and +10.1%, P≤0.05) and PUFA (+8.0 and +9.4%, P≤0.05) has been established in MLD, originating from SL fatteners, compared to both Mangalitsa strains. The total MUFA content was higher in LM and BM than in SL (P≤0.05). A phenotypic correlation between protein content and ashes with water content in MLD has been positive (0.81 and 0.88), while the correlation between water content and total fats has been found to be negative (−0.99). A negative phenotypic correlation between MUFA and SFA, as well as PUFA and MUFA (−0.97 and −0.98) has been established, statistically significant at the level of P≤0.001. A positive phenotypic correlation between PUFA and SFA (0.90), statistically significant at the level of P≤0.001, has been found.

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Acidic and enzymatic coagulation of milk are complex processes which proceed in several phases and are dependent upon many different parameters. The formation of coagulum during lactic-acid fermentation is in fact acidic coagulation of milk. It occurs because of an increase in concentration of lactic acid, which causes a decrease in pH. Enzymatic coagulation of milk has been analytically described by means of mathematical models by many authors. Although enzymatic and acidic coagulation of milk do not proceed according to identical physical and chemical rules, it is possible to compare them kinetically. The aim of this paper was to combine the kinetics of enzymatic and acidic coagulation of milk and to mathematically present the changes that develop during lactic-acid fermentation of milk. The models presented in this paper enable a more complex mathematical analysis of the coagulation of the protein content of milk during lactic-acid fermentation. Application of the models enables the analysis and comparison of the kinetics of coagulation in different types of milk and various types of fermented dairy products manufactured with lactic acid bacteria. Mathematical combination of coagulation kinetics of the protein complex in milk with reological characteristics of the obtained fermented dairy products enables easier defining of parameters for lactic acid fermentation.

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The immobilization of enzymes has not been reported earlier on the two-dimensional crystalline bacterial cell surface (S-layer). In this study we tested S-layer isolated from Bacillus stearothermophilus PV72 for enzyme (ß-glucosidase, hexokinase and aldolase) immobilization. The carbodiimide method gave yields less than 5%. The yields of co-cross-linking method with glutaraldehyde were enhanced compared to the carbodiimide method, but the yield was higher than 10% only in the case of ß-glucosidase. Because of the fine structure of S-layer, immobilized enzymes could be removed from reaction mixtures only by centrifugation, therefore these preparations were entrapped in calcium alginate gel. The yields of entrapping procedures were between 15% and 37%. It was presumed that the new immobilized ß-glucosidase preparation could be used in a preliminary testing for flavour enrichment of wines. Efficiency of this preparation was compared to that of the immobilized ß-glucosidase on Acrylex C-100 support described earlier. We found that the immobilization of ß-glucosidase on both Acrylex C-100 support and S-layer followed by gel entrapping resulted in active enzyme preparations that could be used for flavour enrichment of wines without enhancing their protein content.

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