The effects of different fiber fractions from sour cherry (Prunus cerasus L.) pomace and fiber modification methods on cake quality.

Sour cherry pomace is the largest byproduct of sour cherry processing with more than 0.4 million tonnes per year. In this study, sour cherry pomace powder (SCPP) has been treated individually or by a combination of microwave (MW), enzymatic hydrolysis, and high pressure to increase soluble dietary fiber (SDF) content. Then, the untreated or treated forms of SCPP, their SDF, and insoluble dietary fiber (IDF) isolates were added (5%) to the reduced-fat cake. Rheological, physical, and textural properties of the full-fat (50%) and the reduced-fat (25% fat) cakes enriched with dietary fiber (DF) were compared. SDF enrichment minimized the negative effect of fat reduction in the cake. Water absorption, mixing tolerance, hardness, and springiness values of the SDF-enriched samples were found as the lowest. Extensibility, energy, weight loss, and cohesiveness values were found to be the highest values with the addition of SDF. All treatments helped to decrease mixing tolerance, dough development, and stability time. MW was the critical treatment for DF modification. Individual MW-treated DF samples increased resistance to extension of the dough samples as compared to the untreated SDF, IDF, and SCPP. Nevertheless, SDF showed better performance in acting as a fat replacer than IDF and SCPP. PRACTICAL APPLICATION: The soluble dietary fiber (SDF) isolate minimized the negative effect of fat reduction in cakes. Water absorption and mixing tolerance of the dough were measured as the lowest. The hardness and springiness of soluble dietary fiber-enriched cakes were found to be the lowest. Extensibility and weight loss reached the highest value when SDF was used. Treatments helped decrease mixing tolerance, dough development, and stability time.

The characteristics of microwave-treated insoluble and soluble dietary fibers from grape and their effects on bread quality.

This study investigated the morphological and hydration properties of untreated and microwave (MW)-treated isolate forms of soluble (SDF) and insoluble dietary fibers (IDF) obtained from grapes. Then, the rheological, textural, and other physical effects of the fibers (5% flour basis) were evaluated on bread quality. For this purpose, grape pomace was valorized as the juice extraction waste. MW significantly improved hydration properties of SDF and IDF by modifying their microstructures (p < .05). SDF had a clean-cut morphology whereas IDF had an indented microstructure with a wrinkled surface. After MW treatment, deep grooves and holes were observed. These variations in the IDF structure were more extensive. DF additions influenced water absorption, mixing tolerance index, dough development time, dough stability, resistance to extension, extensibility, energy of the dough and hardness, cohesiveness, springiness, chewiness, weight loss, specific volume, crust color difference of the bread in comparison with the properties of control samples significantly (p < .05). IDF had especially pronounced effects on the dough and bread characteristics. SDF enrichment provided more comparable results with the control bread than IDF. The originality of this work is to characterize isolated (100% purity) SDFs and IDFs, then discuss their effects on semi (dough) and final (bread) product quality.

The effects of high-pressure, enzymatic, and high-pressure-assisted enzymatic treatment on the properties of soluble dietary fibers and their use in jelly prepared with grape waste extract.

This study aimed to investigate the physicochemical attributes of soluble dietary fibers (SDFs) of grape, which were isolated after enzymatic (using cellulase [0.1 MPa/60°C/30 min]), high-pressure (HP) (100 MPa/60°C/30 min), or HP-assisted enzymatic treatment (using cellulase [100 MPa/60°C/30 min]), then to evaluate textural properties, color, and microbiological load of jelly prepared using grape waste extract and either pectin or SDF types. HP-assisted enzymatic treatment increased glucose adsorption capacity by more than 50%, and the water-holding capacity of SDF more than twofold as compared to the levels measured in untreated-SDF. After treatments, glucose and galactose contents decreased, whereas fructose, mannose, xylose, arabinose, and rhamnose ratios increased. The arabinose ratio increased more than twice by the effect of HP, whereas the xylose content increased almost fivefold with HP-assisted enzymatic treatment. For the textural properties of jelly, HP-assisted enzymatic treated-SDF provided almost double values in gel strength and adhesiveness than those contributed by untreated-SDF. It was followed by HP-treated SDF jelly. The results showed that HP-assisted enzymatic treatment developed more similar outcomes with enzymatic treatment, rather than HP treatment alone. HP-assisted enzymatic hydrolysis is recommended for treating SDF for use in jelly due to its synergistic effect. PRACTICAL APPLICATION: High-pressure-assisted cellulase treatment provided the best properties to SDF for jelly. In combined treatment, impacts of cellulase treatment were more prominent than HP effects. Therefore, the use of HP assistance for enzymatic hydrolysis shortens the processing time. Moreover, the technological and functional properties (water holding, glucose adsorption capacity, and monosaccharide composition) of the combined treated-fiber can improve. In addition, the color and textural properties of the jelly prepared with this treated-fiber can be enhanced. In this way, it may be possible to obtain a good thickening agent. This material can also be an alternative to pectin.