The use of apple pomace flour (APF) as a fibre enrichment strategy was investigated. The aim of this study was to evaluate consumers’ response to intrinsic and extrinsic properties of a bakery premix product when using APF. Apple pomace, a by-product from the juice industry, was dried and ground. APF is high in carbohydrates (47.47%) and fibre (38.48%), and it was used to partially substitute wheat flour and sugar in a cake premix. Acceptability, health, and nutrition questions were evaluated with and without information in terms of regular and fibre-enriched cake. The regular cake score was not affected by information, while the enriched cake’s score increased with information. Three clusters were identified. Cluster 1 (29%) showed high liking scores for regular cake, cluster 2 (31%) for the fibre-enriched cake, and cluster 3 (40%) showed similar liking for both. Consumers described the samples and ideal cake using a check-all-that-apply (CATA) questionnaire. Penalty analyses explained differences in acceptability among consumers. Healthiness, tastiness, and fibre content were the main reasons to buy the enriched cake for cluster 2; taste for consumers in cluster 1; and healthiness and taste for consumers in cluster 3. APF as a functional ingredient may be a consumers’ choice as a sustainable use of apple pomace.

This study aimed to determine the effect of the extrusion process on the nutritional and bioactive profiles of brewer’s spent grain (BSG), contributing to nutrition security by applying a circular economy concept. Response surface methodology was used to optimize the effect extrusion parameters (moisture content, screw speed, and barrel temperature ) had on BSG’s soluble dietary fiber, free glucose, and overall antioxidant capacity. Proximate composition analyses, amino acid profile, extractable polyphenolic content, and antioxidant capacity of BSG and brewer’s spent grain extruded under optimal conditions (BSGE) were carried out. Food safety was analyzed by their microbiological quality, gluten, and acrylamide content. Optimal extrusion conditions were 15.8% of moisture content, 164.3 revolutions per min and 122.5 °C. BSGE presented 61% more soluble dietary fiber than BSG, lower digestible starch, 0.546% of free glucose, and protein quality parameters mostly like those reported for egg, soy, and milk. Despite this, BSG’s overall antioxidant capacity was not improved after thermomechanical processing; BSGE had significantly higher extractable polyphenolic content in its alkali extracts, which were determined qualitatively by high-performance liquid chromatography quadrupole time-of-flight assay in its hydro-alcoholic acid extracts. Furthermore, although it is not gluten free, BSGE is a safe food ingredient with acceptable microbiological quality and no acrylamide.

The aim of this work was both to formulate three different fibre-enriched products by the addition of Brewery Spent Grain (BSG), and to evaluate the impact of this fibre enrichment on sensory quality, acceptability, and purchase intention under blind conditions. BSG was incorporated into bread, pasta, and chocolate milk at levels of 8.3%, 2.8%, and 0.35% (w/w), respectively. The fibre-enriched products and their regular counterparts were evaluated together by consumers through a CATA questionnaire, the EsSense 25 Profile, an overall acceptability rating, and a purchase intention ranking. Although fibre-enriched bread and chocolate milk ranked lower in overall acceptability compared with their counterparts, no significant difference was found for fibre-enriched pasta (p > 0.05). Purchase intention did not differ significantly for both bread and pasta (p > 0.05), yet the reasons for purchasing them differed significantly (p < 0.05). Consumers recognised the fibre enrichment in these two products and, therefore, were willing to partially compromise on sensory attributes. The fibre-enriched chocolate milk, nonetheless, scored significantly (p < 0.05) lower in purchase intention than the control. This work demonstrates that the effect of BSG addition is product-specific, and that fibre perception makes consumers feel more confident.

This work aimed to analyse the effect of particle size on bioactive compounds of different by-products. Orange, apple, and grape-wine by-products obtained from industrial production were dried and ground at two sizes: 1 mm and 0.5 mm. Pomaces were analysed in composition (protein, fat, carbohydrates, moisture, and ash contents) and bioactive compounds (total phenol content by Folin– Ciocalteu method and antioxidant capacity by FRAP assay) and submitted to an in-vitro digestion. FESEM was used to observe the microstructure of samples. All pomaces showed high fibre content (21.7, 31.2, and 58.9 g/100 g, in apple, orange, and grape pomace respectively). Total phenol content in raw material was higher in grape > orange > apple, with no differences (apple) or slight differences (grape and orange) between 1 mm and 0.5 mm particle size. Grape pomace was observed as a porous, more accessible structure, where extracting polyphenols was easier. Orange pomace’, was compact and apple pomace structure was even more compact hindering the raw materials polyphenol extraction. After digestion, total phenol content increased in orange and apple pomace for both particle size. In apple, bioaccessibility of phenolic compounds showed a 5 fold increase for 1 mm sample size and a 4 fold increase for 0.5 mm sample size. In orange, for both sizes bioaccessibility increased but to a lesser extent (2.4 fold). In the case of grape pomace, although polyphenol content decreased after digestion (0.7 fold for both sizes), they showed the highest antioxidant capacity. Regarding the effect of particle size on total polyphenol content and antioxidant capacity, no trend was found in this work for the fruit pomaces studied. In the case of grape and apple, grinding at 1 mm should be adequate regarding antioxidant capacity while in the case of orange, it may be better to use a pomace ground at 0.5 mm.

This study aimed to evaluate the nutritional value and potential health claims for reduced sugar biscuits containing extruded brewers' spent grain (EBSG) and fructooligosaccharides (FOS). One traditional biscuit with added sugar and three reduced sugar biscuits containing 15.2 % FOS and EBSG (0, 8 and 17 %), with nutrition claims "high in fiber" and "source of protein" for those containing 17 % of EBSG, were formulated. Biscuits were characterized by analysis of nutrients and bioactive compounds before and after digestion under in vitro enzymatic oral-gastro-intestinal and colonic fermenting conditions. The bioaccessibility of antioxidants, anti-inflammatory and antidiabetic compounds in biscuits' intestinal digests and short-chain fatty acids in colonic samples was analyzed. EBSG-added biscuits showed significantly lower (p < 0.05) glucose intestinal bioaccessibility and significantly higher (p < 0.05) phenolic compounds intestinal bioaccessibility compared to biscuits without EBSG. EBSG-added biscuits showed significantly (p < 0.05) higher in vitro antidiabetic potential than the other did. Moreover, the intestinal digest of biscuits containing 17 % EBSG exhibited significantly (p < 0.05) better in vitro inhibition of intracellular ROS formation and in vitro anti-inflammatory properties. FOS addition (p < 0.05) significantly improved the production of butyric acid while EBSG did for valeric acid which possess chemoprotective effect. In conclusion, the combined use of FOS (15.2 %) and EBSG (17 %) allowed obtaining a human healthier snack formulation for satisfying consumers' demands and achieving nutrition security.

The aim of this work was to obtain, by water extraction, antioxidant dietary fiber from orange juice byproducts. Extractions were performed to orange pomace powder (OPP) varying temperature (55, 65, 75°C) and time (30, 45, 60 min). Two fractions (sediment and supernatant) were obtained from the water extractions and extractable polyphenolic content, antioxidant capacity, total carotenoid content (TCC), and bioaccessibility were determined. Results showed that at 75°C and 45 min the best combination of antioxidant capacity for both fractions is obtained. Under this condition, the sediment is a potential source of antioxidant dietary fiber. Supernatant is rich in bioaccessible polyphenols, associated to soluble fiber as majority component of dietary fiber. Moreover, the water extraction increased the bioaccessibility of polyphenols and carotenoids contained in the OPP. Therefore, both fractions are a potential source of functional food ingredients and orange juice byproducts were entirely revalued. Practical applications The present study suggests an extraction method for orange juice byproducts. Following the principles of green extraction, the technique proposed consists of a water extraction (free of solvents), does not produce waste and is of easy industrial application. As a result, two potential food ingredients with different functional and technological properties are obtained. Therefore, orange juice byproducts are completely revalued and a solution for the management of these byproducts is presented. In addition, the two functional ingredients obtained in this study are a step in the right direction for the development of new functional food formulations.