Optimization of date seed oil extraction using the assistance of hydrothermal and ultrasound technologies

Green extraction technologies for valorization of date seed waste to achieve sustainable development goals: Biofunctional and innovative food applications

Date processing industries generate substantial quantities of waste, including date seeds, which present disposal challenges and environmental concerns. Traditionally, date seed waste has been discarded through landfilling, open burning, or dumping, leading to soil, air, and water pollution. However, with increasing awareness of environmental sustainability and resource conservation, there is a growing interest in valorizing date seed waste using green extraction technologies and innovative food product development approaches for date seed valorization. Therefore, this review aims to explore the biochemical composition of date seeds and the application of green extraction technologies for recovering bioactive compounds. Moreover, this review focuseson the development of date seed-based functional foods, highlighting their applications in bakery, meat products, and beverages. Date seed waste contains both essential (e.g., amino acids, dietary fiber, minerals, etc.) and non-essential (e.g., phenolic compounds, oil, etc.) bioactive nutrients. Compared with traditional methods, green extraction technologies, such as ultrasound-assisted, microwave-assisted, sub or supercritical, enzymatic-assisted extraction, and microbial fermentation have significantly improved extraction efficiency. The incorporation of date seed in the development of breads, cookies, meat products, and beverages (date seed coffee and functional drinks) can enhance bioavailability, stability, and sensory attributes, while preserving the bio-functionality and health benefits. Moreover, date seed valorization can contribute to Sustainable Development Goals 2, 3, 12, and 13. In general, the utilization of date seed waste for the development of innovative food products presents a sustainable solution that is beneficial for both the environment and human health.

Optimization of the Microwave-Assisted Extraction Conditions for Phenolic Compounds from Date Seeds

Date seeds, often discarded during industrial processing, are an underexploited by-product rich in polyphenols with significant antioxidant potential. This study explores the extraction of polyphenols from date seeds using microwave-assisted extraction (MAE) with an organic solvent. The extraction process was optimized using response surface methodology (RSM), focusing on extraction time, ethanol concentration, and temperature. The optimal extraction conditions were 46% (v/v) of ethanol, at 62 °C and for 27.3 min. Under these optimized conditions, the extraction yield and total phenolic content of the extract are 12.5% and 59 mg gallic acid equivalent g-1 of date seed, respectively, as confirmed by the experimental tests. The extract's antioxidant activity was confirmed through DPPH, ABTS, and FRAP assays. High-performance liquid chromatography with diode-array detection (HPLC-DAD) identified major phenolic compounds, including procyanidin B1, catechin, quercetin-3,5'-di-O-glucoside, epicatechin, procyanidin B, and syringic acid, alongside eight other tentatively identified compounds. These findings underscore the potential of MAE as an environmentally friendly technique for producing polyphenol-rich extracts from date seeds, adding value to this by-product and opening avenues for its application in food and nutritional products.

Strategies for the Valorization of Date Fruit and Its Co-Products: A New Ingredient in the Development of Value-Added Foods

Date palm trees (Phoenix dactylifera L.) are traditionally cultivated in South-West Asia and North Africa for date fruit consumption, although in recent years, its consumption has increased worldwide, and its cultivation has spread to other areas of America, sub-Saharan Africa, Oceania, and Southern Europe. During date fruit processing, several types of by-products are generated, such as low-quality dates or seeds, which along with date fruit, represent an excellent source of dietary fiber and bioactive compounds such as flavonoids, tannins, carotenoids, tocopherols, and tocotrienols. Therefore, this review provides information on the processing of dates fruit and the value-added by-products generated from them as well as their applications in different types of foods for the development of foods with an enhanced nutritional and functional profile. The incorporation of date fruit and their co-products in food formulations will help to cover the current consumer demands for foods made with ingredients of natural origin and with health properties beyond the merely nutritional.

Date Seed: Rich Source of Antioxidant Phenolics Obtained by Hydrothermal Treatments

The growing interest in natural compounds is helping to improve the management of agro-industrial by-products such as the date seed as sources of such compounds. In this work, the application of a hydrothermal treatment at 160 and 180 °C for 60 min was studied to achieve the solubilization of its phenolic components and sugars in order to obtain biologically active extracts. The percentage of phenols and total sugars in the final extracts were very similar, at 45 and 25% for the 160 and 180 °C treatments, respectively. The treatment at a higher temperature allowed greater solubilization of other components. The antioxidant activity was measured as free-radical scavenging capacity. For the DPPH^• method, expressed as EC50, the results were 0.34 and 0.37 mg/L, the TEAC values for the ABTS^• method were 6.61 and 3.28 mg/g dried extract, and the values obtained by the ORAC method were 12.82 and 9.91 mmol Trolox/g dried extract, for 160 and 180 °C, respectively. All these values are higher than those of other plant extracts and extracts obtained using the whole date. Therefore, the date seed is a very important source of phenols, and through thermal and chromatographic processes, it is possible to obtain extracts with high antioxidant activity.