Date fruit (Phoenix dactylifera L.) has always occupied an important place in the diets of people in the Arab world. In spite of the enormous socioeconomic transformation that has taken place in this part of the world, date fruit continues to form an essential component of the daily diet.
Unlike many other fruits, dates can be consumed or used for human consumption in every stage of fruit development. Date fruit is usually classified into four main maturity stages, i.e., kimri, khalal, rutab, and tamer (Hussein, 1970). Kimri stage fruit is young, green in color with hard texture, thus can be used for the preparation of pickles and chutney. Depending on the cultivar, the date fruit changes its green color during the next stage.
The khalal (or bisr) stage date fruit attains maximum size and weight; develops a typical yellow, purplish-pink, red, or yellow-scarlet color but retains a firm texture and is largely consumed raw as fresh fruit or can be used for jam, butter, or dates-in-syrup (Al-Hooti et al., 1995b). During the rutab stage, half of the fruit becomes soft, less astringent, and sweeter but darkens in color and can be used for jam, butter, date bars, and date paste. Rutab stage fruits of a few cultivars are being popularly consumed as fresh.
During the final or ripe stage, tamer, the whole fruit attains maximum total solids, highest sweetness and lowest astringency with a dark brown color, a soft texture, and a wrinkled appearance. The physical appearance of a few date cultivars at various stages of maturity is shown in Figures 22.1a–g. For prolonged shelf life and storage, tamer stage fruits can also be sun dried.
A major portion of the date produce enters world trade as tamer fruit for human consumption (Mikki et al., 1986). In the Arabian countries, the value and importance of the date palm tree and its fruits have immense importance.
Every household feels proud to grow at least one tree in their backyard for fruit production.
Date tree is also mentioned and honored in the Holy Quran, and recommended by the Prophet—“Peace Be Upon Him.” Date fruit is known to be a rich source of carbohydrates (mainly glucose and fructose sugars) and certain vitamins, minerals, and dietary fiber (Al-Hooti et al., 1997f). Date fruit is cherished for
its flavor and nutritive value all over the Arab world, as this plant is well suited to grow in arid regions where there are hot and dry climates with limited rainfall. Date trees are usually propagated vegetatively by offshoots. The trees grown from seeds show high genetic heterozygosity that result in not true-to-type male and female plants (Toutain, 1967). To overcome
these drawbacks of longer generation times and genetic heterozygosity, newly emerging tissue culture techniques are now being employed for the propagation of date palm trees (Zaid, 1986; Sudhersan et al., 1993a, b). Recent research is producing a lot of evidence to strengthen the evidence of a vital link between the food we consume and our ultimate health.
Our knowledge about the beneficial role of various food constituents (such as date fruit nutrients) in the prevention and treatment of various disease conditions is growing rapidly. New terms, such as functional foods, medical foods, nutritional foods, hypernutritional foods, designer foods, therapeutic foods, super foods, prescriptive foods, nutraceuticals, and pharmafoods, are being commonly used in one context or another by food scientists as well as by consumers. Generally speaking, functional food can be defined as any food that provides benefits to one’s health, physical appearance, endurance, or state of mind (mood) in addition to its usual nutritive value.
Japan has been a leader in stimulating the growth of the functional food market, but this trend is picking up worldwide, especially in the past 10 years.
The functional food areas relating nutrition and health will definitely revolutionize the food industry in the future. It is predicted that these foods will be the fastest growing segment of the food industry during the coming decades (Kevin, 1995).
Keeping in view the importance of date palm trees and date fruits to this Arabian region, the history of date cultivation, cultivars, production, marketing, physicochemical characteristics, preharvest treatments, postharvest handling of fresh fruits, storage problems, nutritive value and health benefits, date-fruit-based value-added products, standards, regulations, and future research needs are covered in this chapter.