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The objective of this study was to evaluate, from a technological and nutritional point of view, the chemical composition and functional properties of the industrial winemaking by-products, namely skins, stems and lees. The chemical and physical characteristics, as well as the functional properties (fat and water retention and swelling capacity, antioxidant capacity, and their prebiotic effect), of the dietary fibre of these by-products were studied. The results showed that the skins, stems, and lees are rich in fibre, with the stem fibre containing the highest amounts of non-extractable polyphenols attached to polysaccharides with high antioxidant activity and prebiotic effect. Lee fibre had the highest water retention capacity and oil retention capacity. The results reveal that winemaking by-products could be used as a source of dietary fibre with functional characteristics for food applications.

The results of the study of the physicochemical properties of the high-molecular-weight soluble and insoluble components of nectarine cell walls obtained by fruit treatment under conditions that modulate of gastric digestion are presented. Homogenized nectarine fruits were sequentially treated by natural saliva and simulated gastric fluid (SGF) at pH 1.8 and 3.0. The isolated polysaccharides were compared with polysaccharides obtained by sequential extraction of nectarine fruit with cold, hot, and acidified water, solutions of ammonium oxalate and sodium carbonate. As a result, high-molecular-weight water-soluble pectic polysaccharides, weakly bound in the cell wall, were dissolved in the simulated gastric fluid, regardless of pH. Homogalacturonan (HG) and rhamnogalacturonan-I (RG-I) were identified in all pectins. It was shown that their quantity and ability to form highly viscous solutions determine high values of the rheological characteristics of the nectarine mixture formed under simulated gastric conditions. The modifications occurring with the insoluble components under the influence of acidity of SGF were importance. They determined difference in the physicochemical properties of both the insoluble fibres and the nectarine mixtures. • The weakly bound pectin in the cell wall of nectarine fruit is soluble in SGF. • No degradation of pectin is observed during the incubation of nectarine fruit in SGF. • Incubation in SGF decrease hardness and viscosity of nectarine mixture. • Nectarine insoluble fibre have water hydration and glucose adsorption properties. [ABSTRACT FROM AUTHOR]

The effects of in vitro gastric digestion conditions on the properties of the soluble (SC) and insoluble (IC) components of apple cell walls were investigated. Apple fruits were homogenized and successively treated in natural saliva (3 min, 37 °C) and in simulated gastric fluid (SGF, 2 h, 37 °C). The incubation pH (5.0, 3.0, 1.8) and the ratio of apple mixture to SGF (1:0.05, 1:0.5, 1:1, v/v) were varied. Pectin (GalA 74 wt%, Mw 1800 × 103 g/mol, yield 1.9–2.4%) was a major high-molecular-weight component of SC obtained at pH 1.8, whereas at pH 3.0 and 5.0, proteins (41–55 wt%) and phenolic compounds (2.7–3.1 wt%) were dissolved together with pectins (15–24 wt% GalA, Mw 28-33 × 103 g/mol, yield 0.6–0.8%). Rhamnogalacturonan-I (RG-I) and homogalacturonan (HG) were identified in all pectins. HG was the major component of pectins extracted at pH 1.8; RG-I was the major component of pectins extracted at pH 3.0 and 5.0. The dissolution of cell wall pectins of apple fruits in SGF increased the viscosity of the SC of the apple mixture, decreased the hardness of the apple mixture, increased the water retention and water swelling capacity of the IC, and improved the capacity of high-molecular-weight soluble and insoluble components to retard glucose diffusion. The difference in surface morphology of insoluble components obtained at different values of pH incubation was observed under a SEM. [Display omitted] • The pH affects solubility of apple cell wall pectins during incubation in SGF. • HG was the major component of pectins extracted at pH 1.8 • RG-I was the major component of pectins extracted at pH 3.0 and 5.0 • Incubation at pH 1.8 enhances the hydration properties of insoluble components. • Pectin and insoluble components isolated at pH 1.8 similarly inhibit glucose diffusion. [ABSTRACT FROM AUTHOR]

According to recent knowledge, dietary fibre contains more constituents, which due to their physico-chemical properties (solubility, viscosity) modulate the nutrient digestion by different mechanisms. The aim of this review is to present recent knowledge of dietary fibre, particularly its effect on digestibility of protein and fat and its consequences for diet formulation for growing and fattening pigs. The authors reviewed the relevant literature from the last 15 years and concluded that each 1 g NDF/kg diet increment results in a mean reduction of between 0.03 and 0.08% of ileal apparent protein digestibility and 1 g NDF/kg dry matter reduces the digestibility coefficient of energy by approximately 0.1%. The effect of different types of fibre on nutrient digestibility has not been quantified; however, soluble fibre reduces the apparent and true ileal digestibility of protein and amino acids as well as the fat and the energy more than insoluble fibre. Therefore, it is necessary to develop regression equations that compute the reduction in ileal digestibility of nutrients as a function of different types of fibre. [ABSTRACT FROM AUTHOR]

Abstract: The chemical composition and the contents of resistant starch and soluble and insoluble dietary fibre of pea (Pisum sativum L.), common bean (Phaseolus vulgaris L.), chickpea (Cicer aretinum L.) and lentil (Lens culinaris Med.) legumes, were studied. Raw and freeze-dried cooked samples were used, both in the form of flour. Protein values of the legumes ranged from 18.5 to 21.9g/100g for the raw grains and from 21.3 to 23.7g/100g for freeze-dried cooked legumes. Chickpea stood out for the highest lipid content (p <0.05), the lowest insoluble fibre values, and soluble dietary fibre not detected. The average content of resistant starch found in the legumes did not differ statistically (p >0.05), being 2.23±0.24g/100g for freeze-dried cooked legumes, and showing a slight reduction in comparison to the raw form. [Copyright &y& Elsevier]

The objective of this study was to evaluate, from a technological and nutritional point of view, the chemical composition and functional properties of the industrial winemaking by-products, namely skins, stems and lees. The chemical and physical characteristics, as well as the functional properties (fat and water retention and swelling capacity, antioxidant capacity, and their prebiotic effect), of the dietary fibre of these by-products were studied. The results showed that the skins, stems, and lees are rich in fibre, with the stem fibre containing the highest amounts of non-extractable polyphenols attached to polysaccharides with high antioxidant activity and prebiotic effect. Lee fibre had the highest water retention capacity and oil retention capacity. The results reveal that winemaking by-products could be used as a source of dietary fibre with functional characteristics for food applications. [ABSTRACT FROM AUTHOR]