Effect of Addition of Green Coffee Parchment on Structural, Qualitative and Chemical Properties of Gluten-Free Bread

Plant-Based Antioxidants in Gluten-Free Bread Production: Sources, Technological and Sensory Aspects, Enhancing Strategies and Constraints

The recognized contribution of antioxidant compounds to overall health maintenance and spotted deficiencies in celiac patients' diets has driven more intensive research regarding antioxidant compounds' inclusion in gluten-free bread (GFB) production during the last decade. The presented review gathered information that provided insights into plant-based antioxidant sources which are applicable in GFB production through the resulting changes in the technological, sensory, and nutritional quality of the resulting antioxidant-enriched GFB. The influence of the bread-making process on the antioxidant compounds' content alteration and applied methods for their quantification in GFB matrices were also discussed, together with strategies for enhancing the antioxidant compounds' content, their bioaccessibility, and their bioavailability, highlighting the existing contradictions and constraints. The addition of plant-based antioxidant compounds generally improved the antioxidant content and activity of GFB, without a profound detrimental effect on its technological quality and sensory acceptability, and with the extent of the improvement being dependent on the source richness and the amount added. The determination of a pertinent amount and source of plant-based antioxidant material that will result in the production of GFB with desirable nutritional, sensory, and technological quality, as well as biological activity, remains a challenge to be combated by elucidation of the potential mechanism of action and by the standardization of quantification methods for antioxidant compounds.

Potential Effects of the Different Matrices to Enhance the Polyphenolic Content and Antioxidant Activity in Gluten-Free Bread

Gluten-related disorders, including celiac disease, wheat allergy, and non-celiac gluten sensitivity, have emerged as a significant phenomenon affecting people worldwide, with an estimated prevalence of nearly 5% globally. The only currently available treatment for this disease involves the exclusion of gluten from the diet, which is particularly challenging in the case of bakery products. Gluten-free bread (GFB) presents certain disadvantages when compared to traditional wheat bread, including inferior sensory attributes, technological characteristics, and lower protein and fiber content. Numerous studies have focused on strategies to improve these aspects of GFB. However, there are limited reviews regarding the content of the bioactive compounds of GFB, such as polyphenols. Polyphenols are molecules found in various foods that play a vital role in protecting the body against oxidative stress. This is particularly relevant for individuals with gluten intolerance or celiac disease, as they often experience increased oxidative stress and inflammation. Therefore, the objective of this review is to explore the use of different strategies for increasing the polyphenolic content and the antioxidant properties of GFB. Gluten-free cereals and pseudocereals are the most used matrices in GFB. Buckwheat can be a valuable matrix to enhance the nutritional profile and antioxidant properties of GFB, even more so when the whole grain is used. In the same way, the addition of various by-products can effectively increase the bioactive compounds and antioxidant activity of GFB. Furthermore, regarding the contribution of the phenolics to the bitterness, astringency, color, flavor, and odor of food, it is essential to analyze the sensory properties of these breads to ensure not only enriched in bioactive compounds, but also good consumer acceptance. In vitro studies are still in few number and are very important to execute to provide a better understanding of the bioactive compounds after their consumption.

Influence of Coffee Variety and Processing on the Properties of Parchments as Functional Bioadditives for Biobased Poly(butylene succinate) Composites

Fermented polymers like biobased poly(butylene succinate) (BioPBS) have become more relevant as technical substitutes for ductile petrochemical-based polymers but require biogenic functional additives to deaccelerate undesired thermo-oxidative degradation and keep a fully biobased character. In this paper, the influence of coffee parchment (PMT) from two different varieties and processings on the thermo-oxidative stabilization and mechanical properties of poly(butylene succinate) composites up to 20 wt.-% PMT were investigated. Micronized with a TurboRotor mill, both PMT powders differ in particle size and shape, moisture ab- and adsorption behavior and antioxidative properties. It could be shown that pulped-natural PMT consists partially of coffee cherry residues, which leads to a higher total polyphenol content and water activity. The homogeneous PMT from fully washed processing has a higher thermal degradation resistance but consists of fibers with larger diameters. Compounded with the BioPBS and subsequent injection molded, the fully washed PMT leads to higher stiffness and equal tensile strength but lower toughness compared to the pulped-natural PMT, especially at lower deformation speed. Surprisingly, the fully washed PMT showed a higher stability against thermo-oxidative decomposition despite the lower values in the total phenol content and antioxidative activity. The required antioxidative stabilizers might be extracted at higher temperatures from the PMT fibers, making it a suitable biogenic stabilizer for extrusion processes.

Coffee by-products: An underexplored source of prebiotic ingredients

Consumers' demand for foods with high nutritional value and health benefits has fueled the development of prebiotic foods. In coffee industry, cherries transformation into roasted beans generates a large amount of waste/by-products (pulp/husks, mucilage, parchment, defective beans, silverskin and spent coffee grounds) that usually end up in landfills. The possibility to use coffee by-products as relevant sources of prebiotic ingredients is herein ascertained. As a prelude to this discussion, an overview of pertinent literature on prebiotic action was conducted, including on biotransformation of prebiotics, gut microbiota, and metabolites. Existing research indicates that coffee by-products contain significant levels of dietary fiber and other components that can improve gut health by stimulating beneficial bacteria in the colon, making them excellent candidates for prebiotic ingredients. Oligosaccharides from coffee by-products have lower digestibility than inulin and can be fermented by gut microbiota into functional metabolites, such as short-chain fatty acids. Depending on the concentration, melanoidins and chlorogenic acids may also have prebiotic action. Nevertheless, there is still a lack of in vivo studies to validate such findings in vitro. This review shows how coffee by-products can be interesting for the development of functional foods, contributing to sustainability, circular economy, food security, and health.

Effects of green coffee bean flour fortification on the chemical and nutritional properties of gluten-free cake

The objective of this study was the application of green coffee bean flour in gluten-free cakes with different percentages (4, 8 and 15% (w/w)), to evaluate the optimal value for fortification, and the products were characterized based on their centesimal composition and bioactive compounds (caffeine and total phenolic compounds). Significant differences (p ≤ 0.05) were observed in the content of lipids, total dietary fiber, insoluble fiber, energy values, sodium, caffeine, and total phenolics, mainly in the product in which 15% (w/w) green coffee bean flour was added. Caffeine content was only detected and quantified in products with > 8% (w/w) green coffee bean flour, whereas the total phenolic content was detected and quantified in products with > 4% (w/w) green coffee bean flour. Thus, fortification of these products with 15% green coffee bean flour promoted a higher content of total dietary fiber and lower content of lipids, calories, sodium, and increased bioactive compounds. Thus, green coffee bean flour is an excellent alternative for the production of innovative foods.

Potential use of plant-based by-products and waste to improve the quality of gluten-free foods

The food industry generates a large amount of waste and by-products, the disposal of which has a negative impact on the environment and the economy. Plant-based waste and by-products are rich in bioactive compounds such as dietary fiber, proteins, essential fatty acids, antioxidant compounds, vitamin, and minerals, which can be exploited to reduce the nutritional deficiencies of gluten-free products. The latter are known to be rich in fats and carbohydrates but lacking in bioactive compounds; the absence of gluten also has a negative effect on textural and sensory properties. Several attempts have been made to improve the quality of gluten-free products using alternative flours and additives, or by adopting innovative technologies. The exploitation of plant-based by-products would represent a chance to improve both the nutritional profile and the overall quality of gluten-free foods by further enhancing the sustainability of the agri-food system. After examining in detail the composition of plant-based by-products and waste, the objective of this review was to provide an overview of the effects of their inclusion on the quality of gluten-free products (bread, pasta, cake/muffins, biscuits and snacks). The advantages and drawbacks regarding the physical, sensory, and nutritional properties were critically evaluated. © 2021 Society of Chemical Industry.

Chestnut peels and wheat bran at different water level influence the physical properties of pan bread

In breadmaking, dietary fibres are used to improve the nutritional quality of the final products; on the other hand, they may affect the physical and sensory properties. This work aimed to the evaluate, on pan breads, the effect of substituting 3 g of wheat flour with an equivalent amount of fibre rich ingredients: chestnut peels (CP) or wheat bran (WB), in comparison to a traditional wheat bread formulation (C). The effect of four levels of added water (54, 60, 66, 71 g/100 of flour) was also tested. The fibre content of CP (33%) and WB (42%) affected their water binding capacity and, consequently, the quality of the final loaves, according to the different water addition levels. In bread crumb, water content and water activity increased proportionally to the water addition levels, being instead in the crust also affected by the presence of fibres: lower water retention capacity was observed for CP, in comparison to WB and C. The loaf volume resulted higher for C in comparison to WB and CP, in relation to the larger dimensions of the crumb pores, probably due to the interfering effect of fibres during the development of the gluten network. Crumb hardness resulted higher for C at low water addition levels, being instead higher for CP at high water addition levels. CP showed a darker and redder colour, than both WB and C bread, for the presence of the brown pigments carried by chestnut peels. PCA analysis confirmed that more water is required for both the fibre-enriched breads to show characteristics similar to the control loaves.

Application of Broccoli Leaf Powder in Gluten-Free Bread: An Innovative Approach to Improve Its Bioactive Potential and Technological Quality

In comparison to conventional bread, gluten-free bread (GF) shows many post-baking defects and a lower nutritional and functional value. Although broccoli leaves are perceived as waste products, they are characterised by a high content of nutrients and bioactive compounds. The present study evaluated the nutritional value, technological quality, antioxidant properties, and inhibitory activity against the formation of advanced glycation end-products (AGEs) of GF enriched with broccoli leaf powder (BLP). Compared to the control, gluten-free bread with BLP (GFB) was characterised by a significantly (p < 0.05) higher content of nutrients (proteins and minerals), as well as improved specific volume and bake loss. However, what needs to be emphasised is that BLP significantly (p < 0.05) improved the antioxidant potential and anti-AGE activity of GFB. The obtained results indicate that BLP can be successfully used as a component of gluten-free baked products. In conclusion, the newly developed GFB with improved technological and functional properties is an added-value bakery product that could provide health benefits to subjects on a gluten-free diet.