Αρχειοθήκη ιστολογίου

Δευτέρα 24 Ιουνίου 2019

Food Research and Technology

Triticum aestivum ssp. vulgare and ssp. spelta cultivars: 2. Bread-making optimisation

Abstract

In this study, we analysed the bread quality parameters of five bread-making flour from single cultivars, namely two spelt wheats ('Espelta Álava' and 'Espelta Navarra') and three bread wheats ('Bonpain', 'Craklin' and 'Sensas'). The grain from the five cultivars, all grown in an organic system, had been milled using the same procedure. Given that bread-making value of flour is closely linked to the dough rheological properties, the use of flour types other than bread wheat requires us to consider modifying the bread-making process. Therefore, the first step of this study was to optimise the bread-making process seeking to maximise the quality of the five breads. Subsequently, it was found that despite the poorer rheological properties and higher gli/glu ratio, the breads made with the spelt flours had better bread quality parameters: larger loaf volume, higher crumb resilience and lower crumb density and firmness. Principal component analysis separated the two spelt wheats from the other samples. We speculate that the bread-making process itself may be a major factor in the quality found in these breads.



Possibilities of reducing amounts of vicine and convicine in faba bean suspensions and sourdoughs

Abstract

Vicine and convicine may be removed from faba bean by hydrolysis to the corresponding aglycones, divicine and isouramil. For total elimination of their toxicity, further degradation of the aglycones should be shown. The aim of the study was to investigate hydrolysis of vicine and convicine using the enzymatic activity in faba bean in flour suspensions and selected lactic acid bacteria used as starters for faba bean fermentation. In addition, the effect of acidity on the stability of vicine and convicine was investigated. Sourdoughs were used in a baking process to obtain breads as final products. Vicine, convicine, and their aglycones were analyzed using reversed phase high pressure liquid chromatography with UV detection (RP-HPLC-UV). Incubation of the suspensions showed rather small vicine and convicine losses. Acidity itself did not cause losses under the conditions studied, apart from that of convicine at low pH. In sourdough fermentation with strains of Lactobacillus plantarum and Pediococcus pentosaceus, losses of vicine and convicine were dependent on the fermentation temperature and the β-glucosidase activity of the starter. Compared to fermentation at 20 °C, more intense acidification at 25 °C resulted in decrease of vicine up to 85% and convicine up to 47%. Levels of vicine and convicine in breads were comparable to levels in sourdoughs. Furthermore, the aglycones were not detected from breads.



Prophylactic properties of Bacillus subtilis in a bovine β-lactoglobulin sensitized mice model

Abstract

Probiotics have gained considerable attention in recent years due to their biotechnological and immunomodulatory properties. The proteolytic activity and the protective effect of Bacillus subtilis isolated from Algerian goat milk preventing the development of allergic reactions were determined. On the base of SDS–PAGE analysis and the increase of detectable α-NH2 groups, it can be concluded that the isolated isolate has high proteolytic activity. Oral administration of studied Bacillus subtilis DAF442 resulted in significantly lower titers of anti β-lactoglobulin IgG and IgE. This was correlated with a significant decrease in the anaphylactic response ex vivo as measured by reduced short circuit current (Isc) and epithelial conductance (G) and in vivo in mice. Bacillus subtilis DAF442 pretreatment promoted an important protection against changes in intestinal morphology induced by β-lactoglobulin. Hence it can be concluded that studied Bacillus subtilis strain with high proteolytic activity can modulate effectively the immune response and prevent allergic reactions against β-lactoglobulin.



Microbiological status based on 454-pyrosequencing and volatilome analysis of gilthead seabream ( Sparus aurata ) fed on diets with hydrolyzed feather meal and poultry by-product meal as fishmeal replacers

Abstract

The effect of two experimental diets with different animal protein sources on sensory, microbiological and chemical attributes of Sparus aurata flesh stored at chilling temperatures were explored through sensory evaluation, tag-pyrosequencing of the 16S rRNA gene (V3–V4 region) and SPME–GC/MS. respectively. The 50% replacement of fishmeal by either hydrolyzed feather meal (HFM) or poultry by-product meal (PBM), did not affect the initial microbial composition of seabream. Differences were observed on spoiled fish indicating that the diet with non-ruminant processed animal protein (PAPs) in combination with the applied storage conditions affect the selection of spoilage microbiota. Minor differences were also detected in volatile compounds profile of PAP-fed seabream showing no strong effect on flesh quality of fish. This research constitutes the baseline for further investigation on the use of non-ruminant PAPs in fish diets in order for aquaculture to produce a high quality of farmed fish for the consumer.



High temperature and heating effect on the oxidative stability of dietary cholesterol in different real food systems arising from eggs

Abstract

Cholesterol, a monounsaturated sterol present in food of animal origin, can be oxidized during food processing and storage, thus generating a series of oxidation products, collectively called oxysterols. These compounds are increasingly considered of potential interest in the onset and development of vascular disease due to their ability to trigger irreversible damage of vascular cells with consequent activation of phagocytes, up-regulation of the expression and synthesis of adhesion molecules and inflammatory cytokines. The understanding of the conditions, in the presence of which the cholesterol oxidation occurs in foods, could certainly help to prevent the accumulation of oxysterols, allowing to avoid harmful effects on human health. The aim of this work was to verify the presence of 7-ketocholesterol, the most representative of oxysterols family, in eggs and derivative obtained through different procedures of cooking. In the light of our results, we confirmed that the temperature and the lipid nature of the food matrix are closely related to the oxidative stability of cholesterol in foodstuffs. In particular, we tested 7-ketocholesterol formation in the presence of palm oil, rich in saturated fatty acids, or soybean oil, rich in polyunsaturated compounds.



Effect of drying processes in the chemical, physico-chemical, techno-functional and antioxidant properties of flours obtained from house cricket ( Acheta domesticus )

Abstract

The aims of this study were determine (1) the chemical composition (2) the physico-chemical properties (3) the fatty acid profile (4) the techno-functional and (5) the antioxidant properties of flours obtained from house cricket (Acheta domesticus) using two different methods of drying. In thermal drying cricket flour (TDCF) and lyophilized cricket flour (LCF) high content of protein (62.68–67.48%, respectively) and fat (24.91–19.32% respectively) was found. This content was higher than found in several cereal or pseudocereal flours such as wheat, oat or quinoa. Both types of flours showed good techno-functional properties (water and oil holding capacity, Swelling capacity, emulsion and foam capacity and stability) with higher values in LCF than TDCF. The values obtained for techno-functional properties were similar to those found for several flours obtained from cereal or pseudocereal of fruits coproducts. In LCF and TDFC the main fatty acid detected were linoleic, oleic and palmitic acids. LCF showed stronger radical scavenging (7.18–2.82 mg Trolox equivalent/g, respectively), reducing (0.24–0.15 Trolox equivalent/g, respectively) and chelating capacity (43.78–32.23 µg EDTA/g, respectively) than TDCF. Due to the protein and fat content, the good techno-functional and antioxidant properties the flours obtained from house cricket could be used as food ingredient in the development of novel foods.



Spruce galactoglucomannan-stabilized emulsions as essential fatty acid delivery systems for functionalized drinkable yogurt and oat-based beverage

Abstract

The food industry has a considerable demand for functional foods, such as emulsions as delivery system for omega-6 and omega-3 fatty acids. Such delivery systems must be stabilized, ideally with a compound that fulfills the criteria for both functionality and sustainability. Spruce galactoglucomannans (GGM) are novel, wood-derived, natural, value-added, versatile, multi-purpose emulsifiers that can physically stabilize oil-in-water emulsions while simultaneously protecting the oil phase against oxidation. In this study, we present for the first time the use of GGM-stabilized emulsions as complex multicomponent delivery systems for omega-6 and omega-3 fatty acids, i.e., (1) cod liver oil in drinkable yogurt and (2) oat oil in a gluten-free vegan beverage. The emulsions and the resulting functionalized beverages were characterized in terms of their physical stabilities. In addition, functionalized, drinkable yogurt was characterized in terms of the oxidative stability of the oil. Results highlighted that oil droplets stabilized with GGM were stable during storage, against thermal treatment, upon addition into the beverages, and GGM protected cod liver oil against oxidation in drinkable yogurt. The results reported here highlight the vast potential for the use of wood lignocellulose-derived, multi-functional hydrocolloids in modern foods.



Gluten-free bread: effect of soy and corn co-products on the quality parameters

Abstract

Bread is one of the most consumed products in the world and the most studied among the gluten-free foods. Agroindustry co-products are rich sources of functional ingredients, and their chemical composition suggests great potential as a raw material for the food industry. The objective of this study was to evaluate the effect of the addition of 10–30% of okara flour (OF), and 15–45% of corn bran (CB) on the physical and chemical characteristics, sensory profile and consumer preference of gluten-free breads. The addition of higher concentrations of OF resulted in products with decreased technological properties (lower specific volumes, lower slice height, higher firmness, darkening and discoloration of the yellow color). The addition of CB contributed to the maintenance of the yellow color in the crust and crumb and to the increase in the corn flavor intensity. The formulation with 20% OF and 40% CB would be the most interesting, because of the chemical composition (30 µmol of isoflavones aglycones/g of sample and 12.87 g of dietary fiber/100 g of sample and lower content of carbohydrates and caloric value) and similar consumer preference to the other formulations. This formulation had lower discoloration of the yellow color and showed sensory properties suited to consumer preference, such as firmness, porosity, compaction (appearance), corn flavor and moisture (texture). The okara flour and corn bran, soy and corn co-products, respectively, can be used as ingredients in the preparation of gluten-free breads with adequate physical, chemical, technological and sensorial characteristics.



Effect of aroma potential of Saccharomyces cerevisiae fermentation on the volatile profile of raw cocoa and sensory attributes of chocolate produced thereof

Abstract

This research describes on-farm-inoculated cocoa bean fermentation with two selected strains of high aroma-producing Saccharomyces cerevisiae isolated from wine fermentation and their effects on volatile profile of resulted raw cocoa material and sensory characteristics of chocolates produced. Both strains produced suitably flavour-active esters, aldehydes, ketones and pyrazines in raw cocoa. Inoculation of S. cerevisiae at 0.5 g kg−1 significantly improved the volatile profile of raw cocoa beans and enabled production of chocolate with enhanced intense fresh fruits and floral notes. Chocolate produced thereof presented better overall quality attributed whatever the fermentation time in comparison to the chocolate issued from spontaneous fermentation. Our results suggested the ways of using selected enhanced yeasts as S. cerevisiae for on-farm implementation of bean fermentation as promising alternative possibilities to improve the cocoa fermentation process, desirable flavourful raw cocoa material and high-aroma-quality chocolates produced.



Characterization of polyphenolic constituents from Sanguisorba officinalis L. and its antibacterial activity

Abstract

Sanguisorba officinalis L., one kind of perennial plants, has been widely distributed in southern Europe, northern Africa and China. The objective of the present work was to evaluate the antibacterial captivities of polyphenolic extract (PE) of S. officinalis L. on five pathogenic bacteria, including Gram-negative bacteria (Escherichia coli and Salmonella typhimurium) and Gram-positive bacteria (Staphylococcus aureusListeria monocytogenes and Bacillus subtilis). The antibacterial activities were determined by the diameter of inhibition zone, minimum inhibitory concentration and minimum bactericidal concentration tests. The results showed that purified PE had significantly better performance in inhibiting bacteria than crude PE (P < 0.05), and PE had better inhibition effect on Gram-positive bacteria than Gram-negative bacteria. Using LC–ESI–QTOF–MS/MS technology, a total of 44 polyphenolic compounds were tentatively identified, 26 of which have been discussed for the first time in S. officinalis L. Gallic acid, ellagic acid, catechin and their derivatives, which have been identified as antibacterial bioactivities previously, were the major constituents with the amounts of 10, 8 and 11, respectively. Besides, compared with potassium sorbate and sodium benzoate, purified PE with a low concentration had significantly stronger antibacterial ability against all the tested bacteria (P < 0.05), suggesting that purified PE of S. officinalis L. could be a promising source of food preservatives.



Alexandros Sfakianakis
Anapafseos 5 . Agios Nikolaos
Crete.Greece.72100
2841026182
6948891480

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