# Valorization of Date Fruit (_Phoenix dactylifera_ L.) Processing Waste and By-Products: A Review
## 3 Nutritional and Biochemical Composition of Date Fruit and Date By-Products  
Date palms contain abundant essential macro- and micro-nutrients, including carbohydrates, fatty acids, protein, amino acids, minerals and salts, vitamins, and dietary fiber. These compounds can be powerful substances found in dates and date wastes that have the potential to positively influence health. Functional ingredients and dietary supplements could be generated by employing various methods to identify and separate these compounds from date waste. This approach could reduce waste and promote sustainability in the date palm industry (Figure 3).  
The proximate nutritional composition of date fruit and date pit is shown in Table 1. Dates at fresh edible stages may have a moisture content of around 40%, and the high nutritional value of dates is due to their high content of sugar, potassium, calcium, magnesium, and iron as well as vitamins (B1 and B2) and niacin [2; 24; 25]. Date seed contains 8-12% moisture, 60-80% fiber, 4-14% fat, and 5-7% protein. The date seed also contains various phytochemicals, including tannins, flavonoids, terpenoids, saponin, anthraquinone, and alkaloids, as well as essential minerals like potassium and calcium [26]. Date seed fiber contains both soluble and insoluble dietary fibers, and the content of dietary fiber content in seeds is proven to be higher than date pulp [27]. The main components of insoluble fiber are  
Figure 3: Extraction of nutritional and biochemical substances from date waste using various extraction methods.  
hemicellulose, cellulose, and lignin [21]. [PERSON] et al. [27] reported that the high fiber content in date seeds can substitute corn and barley in the diet. Date seeds contain different fiber fractions, including acid detergent fiber, neutral detergent fiber, hemicellulose, cellulose, and lignin. Acid detergent fiber is a combination of cellulose and lignin, ranging from 39.6% to 57.5% [26]. Neutral detergent fiber is a combination of hemicellulose, cellulose, and lignin and ranges from 51.6% to 75.0% [26]. Hemicellulose content in date seeds ranges from 12.0% to 17.5%, while cellulose ranges from 26.1% to 42.5%. Additionally, lignin content in date seeds falls within the range of 7.21% to 11.0% [26].  
The proximate nutritional composition of DPC is also shown in Table 1. [PERSON] et al. [23] also found that magnesium is the mineral with the highest content in DPC, which has an average of 959.5 mg/kg, followed by phosphorus (853.4 mg/kg) and calcium (460.5 mg/kg). Surprisingly, DPC has an average phenolic content value of 17.8 mg/g, which is very close to fresh date fruit (18 mg/g), which showed that high antioxidant compounds remain in DPC after date juice extraction [23]. The composition of DPC was found to vary, with crude protein ranging from 4.1% to 10.5%, neutral detergent fiber at 48%, acid detergent fiber at 25.6%, and nitrogen-free extract at 40.1% [28]. Due to its high fiber and antioxidant content, the DPC left over from processing dates can be useful as an ingredient in healthy foods. The natural brown color of DPC makes it a good option for darker foods like baked goods, and its ability to hold onto the water is an advantage in products like salad dressings and instant soups [23]. The particle size of DPC is also important to consider, as it can affect its chemical composition, nutritional value, and usefulness in different foods [23].