Flour made from fruit by‐products: Characteristics, processing conditions, and applications

Abstract

The disposal of fruit and vegetable by-products has drawn the attention of several sectors worldwide, not only due to the concern over environmental impacts but also due to high ratios of nutrients and bioactive compounds that are found in these nonedible parts. These by-products still have great technological potential, because they can be processed and transformed in cosmetics, pharmaceuticals, food, and other products and biomaterial with high added value. The most common form of incorporating them into food is flour. Drying operations enable waste to keep higher concentration of nutrients, less susceptibility to be attacked by microorganisms (due to low humidity), lower storage volumes, and longer shelf-life. The process of transforming residue into flours can be carried out by different equipment whose goal is to remove moisture. Afterwards, dry products pass through mills to reduce particle size. Then, standardization of granule size is recommended. In the conversion steps, processing conditions are particularly important because they should not cause any loss of nutrients, bioactive compounds, and antioxidant activity to the final product.In view of the need to control production steps, this review aimed at compiling information on the theme found in the literature and at highlighting existing gaps to show the scientific community the importance of studying the factors that affect the quality of dehydrated final products. Practical applicationsThe disposal of fruit by-products attracts the attention of several segments, not only due to the concern with environmental impacts worldwide but also due to the high levels of nutrients and bioactive compounds that are still present in these inedible parts that are not properly used. This review provides nutritional and technological information on fruit residues and their potential for application in food. The most common way of inserting these products in food matrices is through flour, but this process is not just about removing moisture from the product, several factors need to be studied and controlled aiming at the minimum of nutritional and technological losses, reduction of antinutritional factors that may be present in the residues, reduced development of microorganisms, and enzymatic activity, and for these reasons, this review was constructed, to bring the main scientific findings in the literature that reports studies on these subjects to the scientific community. Papaya seed Carica papaya L. Oven drying at 45°C Devi and Khanam (2019) Havai and Calimosa Tray drying at 45°C for 4 days Santos et al. (2014) C. papaya L. Spouted-bed drying 40°C-100°C with 9.24, 9.75, 10.50, and 11.76 m/s of flow air, for 0.5, 1.21, 2.25, 3.29, and 4.0 hr Chielle et al. (2016) C. papaya L. Convective air-drying at 40°C-100°C, air velocity (1-3 m/s) Chielle et al. (2016) Papaya peel Havai and Calimosa Tray drying at 45°C for 4 days Santos et al. (2014) C. papaya Oven drying at 60°C for 48 hr Morais et al. (2017) Freeze drying for 24 hr C. papaya L. Formosa Oven drying at 70°C...

Optimization of gluten‐free muffins made with pineapple peel, banana peel, and pumpkin seed flours

“…Fortes et al (2020) observed that PPF and BPF showed significantly higher soluble fiber levels, and PPF provided the highest insoluble fiber level. According to Larrosa and Otero (2021), fruit by-products are rich in dietary fiber, with the insoluble fraction greater than the soluble fraction. Fruit peels have a high content of dietary fiber, while seeds exhibit high levels of lipids, proteins, and starch (reserve substrates), corroborating with the results found in the present study.…”

“…Modern consumers have changed their food preferences, including natural products like fruits and vegetables, which are recognized sources of bioactive compounds and are known to be associated with several health benefits. The greater volume of production in the food processing industry has led to an increase in the production of by-products and waste, generating large quantities of peels and seeds, which can be inadequately discarded, causing health and environmental problems (Larrosa & Otero, 2021;Sabino et al, 2020).…”

“…The most common way to incorporate these by-products into food formulations is through the flour. The drying operations allow a higher concentration of nutrients, less susceptibility to microbial attack due to the low moisture levels, lower storage volumes, and longer shelf life of these residues (Larrosa & Otero, 2021). According to Fortes et al (2020), pineapple peel flour (PPF) and banana peel flour (BPF) had the highest soluble fibers contents (5.25% and 6.20%, respectively) and PPF the highest insoluble fiber content (45.06%), being an option for food enrichment.…”

Antioxidant Capacity, Antitumor Activity and Metabolomic Profile of a Beetroot Peel Flour

“…In order to promote the use of vegetable residues, the production of vegetable flours is an option, since they can preserve the bioactivity and nutritional properties of the in natura vegetable [ 16 ]. Beetroot peel is promising for the production of flour due to its proximate composition, containing a protein content of almost 7%, a dietary fiber content of 19% and a mineral content of 11% (dry weight basis), as well as bioactive compounds, such as polyphenols, flavonoids and betalains [ 17 , 18 ].…”

Utilization of Fruit Seed-Based Bioactive Compounds for Formulating the Nutraceuticals and Functional Food: A Review

“…Cake formulations having 5 percent to 10% flour generated better results, however, formulations containing more than 10% flour had negative effects on cupcake qualities. Weight, volume, and specific volume increased as the ratios of guava by-products decreased ( 115 ). According to Khalifa et al the cake with a high ratio of guava seed flour had higher ratios than the cake with guava peel; this could be because the cake with a high ratio of guava seed flour has higher protein and fat contents.…”