Composition and Physicochemical Characterization of Fiber-Rich Food Processing Byproducts

Watermelon Rind Dietary Fibers as Natural Source to Enhance Texture of Wheat Bread

The objective of this study was to explore how watermelon rinds (WMRs) and their derivatives, specifically water-soluble polysaccharides (WMRPs) and hemicellulose (WMRH), as sources of dietary fiber, could enhance the quality of wheat bread. The extraction process yielded 34.4% for WMRP and 8.22% for WMRH. WMR, WMRP, and WMRH exhibited promising functional characteristics and were incorporated separately into wheat flour with low bread-making quality (FLBM) at varying proportions (0.5%, 1%, and 1.5% (w/w)). The volume, texture, and crust and crumb color underwent evaluation and were compared to the control. The findings indicated that incorporating WMR notably enhanced the alveograph profile of the dough, demonstrating a more effective impact than the addition of WMRP and WMRH. Adding WMR, WMRP, and WMRH at a 1% concentration to low-quality wheat flour for bread making increased the deformation work values by 16%, 15%, and 13%, respectively, and raised the P/L ratios by 42%, 36%, and 38%, respectively. Additionally, the assessment of the bread highlighted a substantial enhancement in both volume and texture profile when WMR was added, in contrast to the control bread (made with FLBM). These findings underscore that incorporating 1% WMR into FLBM was the most effective means of improving bread quality based on the results of this study.

Dragon fruit peel extract microcapsule incorporated pearl millet and dragon fruit pulp powder based functional pasta: formulation, characterization, and release kinetics study

The pearl millet based functional pasta was formulated by incorporating freeze dried dragon fruit pulp powder and 2% (w/w) microcapsule containing dragon fruit peel extract. The control pasta consisted of 100% pearl millet flour. The other four functional pasta samples consisted of pearl millet and freeze-dried dragon fruit pulp powder (DFP) in the ratio of 95:5, 90:10, 85:15, and 80:20 (w/w), respectively. The inclusion of dragon fruit powder enhanced the swelling index, water absorption index, color, and functional properties of the pasta. The total phenolic content (0.24-0.43 mg GAE/100 g d.w.), antioxidant activity (17.76-30.67%), and betacyanin content (0.149-0.152 mg/g d.w.) of the pasta was increased with the increase of dragon fruit pulp level in the formulation. The release kinetics of phenolic compounds into the simulated gastric juice was modeled using Higuchi and Peppas- Sahlin models. Out of these two models Peppas- Sahlin model (R 2 > 0.980 and R M S E < 1.527 ) found to predict the release of phenolics into simulated gastric juice with respect to time of release when compared with Higuchi model (R 2 > 0.964 and R M S E < 6.126 ). The onset of transition temperature and enthalpy of gelatinization of pasta samples was found to be in the range of 66.321-74.681 °C and increased with the increase of dragon fruit level in the formulation.

Alteration in dough volume and gluten network of lychee pulp pomace bread base on mixture design dominated by particle size

The reducing flavor of whole grain bread has been constantly affecting the consumption desire of a significant proportion of consumers. The study presents the use of lychee pulp pomace (LPP) powder to replace certain proportion of wheat flour and produce wheat bread with better quality, while having minimal effects on the volume and improving the nutritional quality. Distinct particle sizes (60-400 µm) of LPP powder were obtained by superfine or ordinary grinding. Effect of different additive proportions (7-19%) of LPP powder on bread dough quality were studied by constrained mixture designs. The volume of fermented doughs subsequently decreased after adding LPP powder. However, LPP powders with smaller particle sizes were able to minimize this effect due to its higher water-holding capacity. The analyses of gluten network showed that smaller particle sizes of LPP powder resulted in a decrease in surface hydrophobicity and increase in the elasticity and stability of gluten network. Finally, optimum mixture formula was composed of 16% LPP powder with 60 µm particle size and 15% water. The study illustrated the potential to make high-quality bread with small particle size of LPP powder. PRACTICAL APPLICATION: The addition of dietary fiber to wheat flour can adversely affect the dough volume and reduce the dough quality. By reducing the particle size of lychee pulp pomace powder, this adverse effect could be minimized while increasing the content of dietary fiber and bound phenolics in the dough. This provides data for the production of high-quality lychee dough bread.

Extraction and characterization of cell wall polysaccharides from cranberry (Vaccinium macrocarpon var. Stevens) pomace

Cranberries of Stevens variety, mainly used for juice production, were processed into pomace, from which alcohol insoluble solids (AIS) were obtained. The cell wall polysaccharides were sequentially extracted from AIS, and characterized in terms of monosaccharide profile, sugar linkage and molecular weight distribution. Pectic polysaccharides represented more than 90% of the carbohydrates contained in hot buffer (HA), chelating agents (CH) and diluted alkali (DA) extracts. HA extract contained homogalacturonan with 75% being methyl esterified, and pectic arabinan with traces of pectic galactan, type II arabinogalactan and 1,4-β-glucan. CH extract, recovered with the highest yield (11.0% w/w), was composed mainly of homogalacturonan. DA extract included homogalacturonan with 2% methyl esterification, abundant arabinan and galactans and traces of 1,4-β-glucan. Glucomannan, xylan and xyloglucan represented 66% of the carbohydrates present in the last concentrated alkali extract (CA), the rest being pectic arabinan and galactan. High molecular weight polysaccharides (>10² kDa) were identified in all extracts.

Utilization of Food Processing By-products in Extrusion Processing: A Review

The processing of agricultural products into value-added food products yields numerous by-products or waste streams such as pomace (fruit and vegetable processing), hull/bran (grain milling), meal/cake (oil extraction), bagasse (sugar processing), brewer's spent grain (brewing), cottonseed meal (cotton processing), among others. In the past, significant work in exploring the possibility of the utilization of these by-products has been performed. Most by-products are highly nutritious and can be excellent low-cost sources of dietary fiber, proteins, and bioactive compounds such as polyphenols, antioxidants, and vitamins. The amount of energy utilized for the disposal of these materials is far less than the energy required for the purification of these materials for valorization. Thus, in many cases, these materials go to waste or landfill. Studies have been conducted to incorporate the by-products into different foods in order to promote their utilization and tackle their environmental impacts. Extrusion processing can be an excellent avenue for the utilization of these by-products in foods. Extrusion is a widely used thermo-mechanical process due to its versatility, flexibility, high production rate, low cost, and energy efficiency. Extruded products such as direct-expanded products, breakfast cereals, and pasta have been developed by researchers using agricultural by-products. The different by-products have a wide range of characteristics in terms of chemical composition and functional properties, affecting the final products in extrusion processing. For the practical applications of these by-products in extrusion, it is crucial to understand their impacts on the qualities of raw material blends and extruded products. This review summarizes the general differences in the properties of food by-products from different sources (proximate compositions, physicochemical properties, and functional properties) and how these properties and the extrusion processing conditions influence the product characteristics. The discussion of the by-product properties and their impacts on the extrudates and their nutritional profile can be useful for food manufacturers and researchers to expand their applications. The gaps in the literature have been highlighted for further research and better utilization of by-products with extrusion processing.

Whole faba bean flour exhibits unique expansion characteristics relative to the whole flours of lima, pinto, and red kidney beans during extrusion

Determining the impacts of extrusion conditions on extrudate characteristics of whole beans flours is critical to find the suitable types of beans to use for making direct expanded products. Whole bean flours of four different bean types, faba, lima, pinto, and red kidney, were extruded. The influence of barrel temperature (120, 140, and 160 °C), moisture content (17%, 21%, and 25%), and screw speed (150, 200, and 250 rpm) on process and product responses was studied with a corotating twin screw extruder. The barrel temperature, moisture content, screw speed, and variety of bean had significant influence on process and product responses, back pressure (MPa), torque (N·m), specific mechanical energy (kJ/kg), expansion ratio, water absorption index (g/g), and water solubility index (%) (P < 0.05). Faba bean extrudates had a significantly higher expansion ratio compared to other beans (lima, pinto, and red kidney beans) even though faba bean contained significantly higher protein and higher crude fiber contents (P < 0.05). PRACTICAL APPLICATION: The outputs of this research will be helpful to the food industry in the production of high nutrient-dense food products from whole beans by maintaining the expansion and texture of the products. The data should assist to choose the suitable types of whole bean flours and the optimum processing conditions for making direct expanded extruded products.

Dietary fiber sources and human benefits: The case study of cereal and pseudocereals

Dietary fiber (DF) includes the remnants of the edible part of plants and analogous carbohydrates that are resistant to digestion and absorption in the human small intestine with complete or partial fermentation in the human large intestine. DF can be classified into two main groups according to its solubility, namely insoluble dietary fiber (IDF) that mainly consists on cell wall components, including cellulose, some hemicelluloses, lignin and resistant starch, and soluble dietary fiber (SDF) that consists of non-cellulosic polysaccharides as non-digestible oligosaccharides, arabinoxylans (AX), β-glucans, some hemicelluloses, pectins, gums, mucilages and inulin. The intake of DF is associated with health benefits. IDF can contribute to the normal function of the intestinal tract and it has an important role in the prevention of colonic diverticulosis and constipation. SDF is extensively fermented by gut microbiota and it is associated with carbohydrate and lipid metabolism, with important health benefits due to its hypocholesterolemic properties. Due to these nutritional and health properties, DF is widely used as functional ingredients in food industry, being whole grain cereals, pulses, fruits and vegetables the main sources of DF. Also some synthetic sources are employed, namely polydextrose, hydroxypropyl methylcellulose or cyclodextrins. The DF content of cereals varies depending on cultivars, their botanical components (pericarp, emdosperm and germ) and the processing conditions they have undergone (baking, extrusion, etc.). In cereal grains, AX are the predominant non-cellulose DF polysaccharides followed by cellulose and β-glucans, while in pseudocereals, pectins are quantitatively predominant.

Fiber-Rich Food Processing Byproducts Enhance the Expansion of Cornstarch Extrudates

Expansion characteristics of cornstarch-based extrudates incorporating fiber-rich food processing byproducts was explored. Waxy and regular cornstarch were used as the base materials with apple pomace and sugarcane bagasse incorporated at two addition levels (0%, 15%, and 30% w/w). Extrusions were conducted at three different screw speeds (150, 200, and 250 rpm) with other parameters optimized and kept constant. Apple pomace inclusion resulted in higher initial expansion index (4.23 to 5.60) and higher stable expansion index (2.76 to 4.43), but also showed higher shrinkage (8.50% to 34.72%) than sugarcane bagasse extrudates at the same inclusion levels. Inclusion of apple pomace showed potential of producing extrudates with significantly higher expansion than cornstarch control, with relatively lower energy inputs. Extrusion methods used here have the potential to preserve the textural quality and nutritional value of the fiber-enriched extrudates, providing the base for healthier snack food items.

PRACTICAL APPLICATION

Findings from this study can be extended to the other fiber-rich food processing byproducts, such as other fruit and vegetable pomace, cereal brans, and pulse hulls among other materials. This data will help the development of fiber-enriched extruded snacks that would have favorable consumer traits.