Effect of extraction methods on the physicochemical, structural, functional, and antioxidant properties of the dietary fiber concentrates from male date palm flowers

Abstract

The current study evaluates the effect of both aqueous and alkaline extraction methods on the physicochemical, structural, functional, and antioxidant properties of dietary fibers (DF) from male date palm flowers (MDPF). The DF extracted by the alkali treatment (ADF) display a higher DF content as well as lower protein and lipid content than the DF resulting from watery extraction (WDF). The scanning electron microscopy, the Fourier‐transform infrared spectroscopy, and the X‐ray diffraction show that the alkaline treatment contributes to a slight modification of the structural characteristics of ADF leading to better purity and functional properties. The oil holding capacity and the antioxidant activity of ADF have improved compared to the WDF, which makes this concentrate a promoting functional ingredient and a natural antioxidant. Therefore, these findings confirm the wealth of both concentrates in DF, especially ADF, as well as their potential of functional and antioxidant properties, which emphasize their suitability to be used in food applications as functional ingredients. Practical applications Nowadays, studies on the extraction of DF from vegetable waste are of considerable interest in the face of the rising global demand for dietetic food. The male date palm flowers (MDPF), an agricultural waste generated during the period of pollination, are valuable natural sources of DF and antioxidants. The insoluble DF of MDPF could be essential in a balanced diet as they could fight against obesity by creating a feeling of satiety. The presence of antioxidants, which are known for preventing or slowing cell damage caused by free radicals, could contribute to the improvement of the antioxidant properties of the formulated food. The functional properties of DF concentrates from MDPF are able to solve the technical problems of agri‐food industries when used as food ingredients. The use of DF from MDPF, consequently, contributes to the minimization of waste and provides value addition to the by‐product considered as waste in agricultural processing.

Valorization of Date Fruit (Phoenix dactylifera L.) Processing Waste and By-Products: A Review

“…Studies have indicated that these types of fibers found in diets offer several health advantages, such as enhancing the digestive system and minimizing the probability of developing long-term illnesses [109,110]. Several studies have investigated the extraction of dietary fibers from date processing waste using different methods, including enzymatic hydrolysis, acid and alkali treatments, and microwave-assisted extraction [78,111]. The extracted dietary fibers can be used as functional ingredients in the food industry, such as in the production of high-fiber bread, pasta, and snacks, as well as in the development of dietary supplements [112].…”

Research advances in bioactive components and health benefits of jujube (Ziziphus jujuba Mill.) fruit

“…DF can selectively promote metabolism and the proliferation of beneficial bacteria to produce energy and nutrients for the body (Williams et al, 2017). At present, methods for extraction of DF include mainly crude separation, chemical methods, membrane separation, enzymatic methods, enzymatic chemical combination methods, and fermentation methods (Yan et al, 2019;He YY et al, 2020;Karra et al, 2020). Miklavčič Višnjevec et al (2019) performed a modified enzymaticgravimetric method to determine the total, soluble, and insoluble fiber contents of jujube sample Zj2.…”

Modulating flavanone compound for reducing the bitterness and improving dietary fiber, physicochemical properties, and anti-adipogenesis of green yuzu powder by enzymatic hydrolysis

“…Yuzu contains high levels of bioactive compounds, such as flavonoids, phenolic compounds, organic acids, and minerals that contribute to its biological activities, including antioxidant, antidiabetic, anti-inflammatory, neuroprotective, anticarcinogenic, and antihypertensive activities ( Kim et al, 2013 ; Lee et al, 2022 , Nam et al, 2021 ). Moreover, yuzu peel is rich in dietary fiber, primarily composed of cellulose, polysaccharides, lignin, and proteins that give their superior physicochemical properties, enhance their biodegradable properties, and contribute to human health benefits as dietetic ingredients ( Lv, Liu, Zhang, & Wang, 2017 ; Karra et al, 2020 , Nam et al, 2021 ). Therefore, yuzu has been used to produce various food products, such as fruits, sugar-pickled yuzu tea, aroma and flavor additives, and natural ingredients in biodegradable polymers and packaging materials ( Nam, et al, 2021 ).…”