Page 336 - Natural Antioxidants, Applications in Foods of Animal Origin

Antioxidant Dietary Fiber: An Approach to Develop Healthy 315
VetBooks.ir pericarp and seed which constitutes between 10 and 15% of date fruit weight

(Hussein et al., 1998). The date seeds considered as a waste product of many
date processing plants producing pitted dates, date syrup, and date confec-
tionery. Generally, seeds are used as an animal feed; however, could be a
valuable source of DF and phenolics.
Three native sun dried date varieties from Oman (Mabseeli, Um-sellah,
and Shahal) their syrups and by-products (press cake and seed) were examined
for their proximate composition, DF, total phenolics, and total antioxidant
activity (Al-Farsi et al., 2007). Carbohydrate was the predominant compo-
nent in all date varieties, syrups, and their by-products, followed by moisture,
along with small amounts of protein, fat, and ash. The DF content in seeds and
press cakes were found to be 77.75–80.15% fresh weight and 25.39–33.81%
fresh weight, respectively. Among dates, syrups, and their by-products, seeds
had the highest contents of total phenolics (3102–4430 mg of GAE/100 g
fresh weight) and antioxidant activity (580–929 µmol of Trolox equivalents/g
fresh weight). The researcher concluded that date by-products, particularly
seeds serve as a good source of natural antioxidants and could potentially be
considered as a functional food or functional food ingredient.
Al-Farsi and Lee (2008) conducted the work to optimize extraction condi-
tions of phenolics and DF from date seeds. The effects of solvent to sample
ratio, temperature, extraction time, number of extractions, and solvent type
on phenolic extraction efficiency were observed. Two stage extractions,
each stage lasting for 1 h duration at 45 °C with a solvent to sample ratio
of 60:1, was considered optimum. Acetone (50%), and butanone were the
most efficient solvents for extraction and purification, increasing the yield
and phenolic contents of seed concentrate to 18.10 and 36.26%, respec-
tively. The TDF of seeds increased after water and acetone extractions. Nine
phenolic acids were detected in seeds with p-hydroxybenzoic, protocate-
chuic, and m-coumaric acids found to be among the highest. Protocatechuic,
caffeic, and FAs were the major phenolic acids found in the concentrates. It
was suggested that date seed concentrates could potentially be economical
source of natural DF and antioxidants.

8.5.2 VEGETABLE BY-PRODUCTS

8.5.2.1 BRASSICA PLANTS

Epidemiological studies have shown that high consumption of Brassica
vegetables, including cauliflower, cabbages, and broccoli, is associated with