Fahad Y. Al-Juhaimi

Mango (Mangifera indica L.) by-products and their valuable components: a review.

The large amount of waste produced by the food industries causes serious environmental problems and also results in economic losses if not utilized effectively. Different research reports have revealed that food industry by-products can be good sources of potentially valuable bioactive compounds. As such, the mango juice industry uses only the edible portions of the mangoes, and a considerable amount of peels and seeds are discarded as industrial waste. These mango by-products come from the tropical or subtropical fruit processing industries. Mango by-products, especially seeds and peels, are considered to be cheap sources of valuable food and nutraceutical ingredients. The main uses of natural food ingredients derived from mango by-products are presented and discussed, and the mainstream sectors of application for these by-products, such as in the food, pharmaceutical, nutraceutical and cosmetic industries, are highlighted.

Effects of different levels of Moringa (Moringa oleifera) seed flour on quality attributes of beef burgers

Meat of beef patties was partially replaced by different levels (0, 2, 4 and 6%) of Moringa seed flour (MSF). The replacement of meat did not significantly (p ≤ 0.05) affect the chemical composition of the patties. The cooking properties of the patties formulated with MSF improved with the flour level. The thiobarbituric acid value was higher for non-formulated patties than for formulated ones after storage. The addition of MSF slightly reduced the pH of raw patties with the storage time. Patties formulated with MSF had significantly (p ≤ 0.05) lower aerobic plate counts throughout the storage period. As the level of MSF increased, the patties had high lightness (L*) and yellowness (b*) values but low redness (a*) values. A relatively low sensory acceptability was noted for MSF-formulated patties and was slightly reduced at longer storage times, but that of non-formulated ones decreased significantly (p ≤ 0.05) at longer storage times. The results indicated that M. oleifera seed flour has a high potential as a binder for use in beef patty production in addition to its health and nutritional benefits.

Physicochemical, microbiological and sensory evaluation of beef patties incorporated with destoned olive cake powder

The biological efficacy of different concentrations (2%, 4%, and 6%) of destoned olive cake (DOC) as improvers of the quality, storability, and safety of beef patties was investigated. Increasing the percentage of DOC in the patties improved (P≤0.05) the protein and fat contents, cooking yield, moisture and fat retention, total phenolic, and DPPH radical scavenging activity, while the dimensional shrinkage and TBARS showed a progressive reduction. The pH of the patties decreased gradually with the storage time. DOC-incorporated patties showed significantly (P≤0.05) lower total plate count than untreated. Surface color values of raw beef patties were decreased gradually with the storage time. Throughout the storage period, all the sensory traits of non-formulated patties were significantly (P≤0.05) reduced, whereas the formulated patties revealed considerable stability of all characters. Overall, this study identified antioxidant and antimicrobial potentiality of DOC, which could pave the way for its use as an extender of the shelf life of the patties.

Some nutritional characteristics and mineral contents in barley (Hordeum vulgare L.) seeds cultivated under salt stress

Barley (Hordeum vulgare L.) is an important food crop grown worldwide and it is important to investigate the quality of its grain as affected by various environmental conditions. In this study, barley was grown under increasing salt stress (0, 40, 80, and 120 mmol/l of NaCl) and the nutritional quality of its seeds was evaluated for their proximate composition, phenolic compounds and micro- and macro-mineral contents. Phenolic compounds of barley seeds increased significantly from 1.75 (control) to 1.95 mg gallic acid equivalent/g dry weight of barley seed in 120 mmol/l NaCl. Cu, Mg, and Ni contents were decreased whereas Fe, Mo, and Zn contents were increased significantly by increasing salinity. Among the macro-minerals in barley seeds cultivated under salt stress only K contents increased whereas Ca, Mg, P, and S contents were decreased significantly.

Effect of pistachio seed hull extracts on quality attributes of chicken burger

ABSTRACT The effect of pistachio hull water extracts (PHWE) at different levels on quality of chicken burger during storage at 4 ± 1°C was investigated. Differences between treatments parameters means were separated using analysis of variance (ANOVA). There was no significant difference in fat, protein, and ash contents of the burgers. The increase in PHWE levels increased the cooking yield and moisture retention (MR) in the treated burger from 59.82% to 66.99% and from 44.27% to 54.73%, respectively. The treated burgers had significantly (p < 0.05) higher phenolics than untreated. The pH of the burger was decreased with the increase of storage time. As the storage period increased, thiobarbituric acid reactive substance and plate count were increased in untreated burger. The sensory results showed no significant difference in overall acceptability of the burger. The addition of PHWE to chicken burgers improved its quality during storage for up to 10 days at 4 ± 1°C.

Effect of heating process on oil yield and fatty acid composition of wheat germ

In this study, fatty acid composition, antioxidant activity, total phenol and oil content of heat-treated wheat germs were investigated. Results of control samples were compared with heated wheat germs at different temperatures (100, 120, 150 and 180 °C) and times (5, 8 and 11 min). The maximum yield was obtained when heated at 120 °C/11 min with 7.293% and 120 °C/8 min with 7.256%, while the minimum oil content was observed at 100 °C/11 min with 5.794%. Linoleic, oleic acid and palmitic acids were the major fatty acids of wheat germ oil. The most dominant fatty acids of control samples were linoleic (58.382%), oleic acid (18.554%), palmitic acid (12.926%), and linolenic acid (6.848%). The fatty acid composition of wheat germ oil was not significantly affected by the heating treatment. On the other hand, a decrease was observed in antioxidant activity of heated samples. Wheat germ had the highest total phenol content.

Thermosonication process for optimal functional properties in carrot juice containing orange peel and pulp extracts

Aqueous extracts of orange peel and pulp with high total phenolic contents (TPC) (25.94 and 11.38 mg GAE/g extracts, respectively) were employed in the formulation of functional carrot juice and functional juices were treated using thermosonication process. In accordance with Box-Behnken design, 17 runs with 3 variables and 3 levels was applied for the optimization of the carrot juice with peel (CJPL) and pulp (CJPP) extracts. Overlaid contour plots prediction showed that the optimal conditions for CJPL were 125 mL juice volume, 6.50 min ultrasound process time and 52.78 °C ultrasound process temperature for maximum TPC (30.25 mg GAE/100 mL) and DPPH scavenging activity (61.22%). Sample CJPP has maximum TPC (28.94 mg GAE/100 mL) and DPPH activity (55.87%) under optimal ultrasound process conditions of 125 mL juice volume, 5.04 min and 59.99 °C ultrasound process time and temperature, respectively. Optimization of thermosonication showed significant improvements in the quality of functional carrot juice.

Optimization of ultrasonic-assisted extraction of phenolic compounds from fenugreek (Trigonella foenum-graecum L.) seed

ABSTRACT Fenugreek (Trigonella foenum-graecum L.) seed was used for the recovery of phenolic compounds by employing different process modifications of ultrasonic-assisted extraction (UAE). It was observed that a 3-day germination (35°C) process negatively affected the phenolic contents of seed. Preliminary studies found that maximum quantities of phenolic compounds obtained from germinated and un-germinated seed were 5.882 and 7.534 mg GAE/g when extraction was carried out at 35°C for 30 min using ethanol (30%) as solvent. Un-germinated seed was used for further studies. In order to improve total phenolic compound recovery, Box–Behnken experimental design, regression analysis and response surface methodology were applied following the initial studies. The optimum UAE conditions were established as 38°C temperature, 32 min time and 33% ethanol for the maximum total phenolics (8.41 mg GAE/g DW). Fenugreek seed extract also showed a good radical scavenging activity (62.74 ± 1.66%).

CHAPTER 4:The Chemistry/Biochemistry of the Bioconversion of Isoflavones in Food Preparation

Soy is the principal plant that produces isoflavones (1–2 mg g−1). Daidzein 8-C-glucoside is known as puerarin and it is often the major constituent of isoflavone dietary supplements. Isoflavones in the soybean are converted into 7-O-β--glucosides by a glucosyltransferase and then to their 6′′-O-malonate forms by a malonyltransferase. Fermented soyfoods, such as miso and tempeh, contain the unconjugated isoflavone aglucones, whereas non-fermented soyfoods, such as soymilk, tofu, soy flour, soy protein concentrate and isolated soy protein, contain their β-glucoside conjugates. Soy isoflavones are found predominantly in the glycoside form and in low concentrations as aglycones. In general, fermentation causes the removal of the glucosidic group, releasing the isoflavone aglucone. The fermentation process carries out the bioconversion of isoflavones to increase their bioavailability such as in the form of genistein and daidzein which are bioactive isoflavones. The β-glycosyl bond of isoflavones glycosides is cleaved to produce their aglycones by microbes during fermentation. The reaction for the bioconversion of isoflavone-glycoside into isoflavone-aglycone can be enhanced by the use of enzymes such as β-glycosidase.

The Effect of Solvent Type and Roasting Processes on Physico-Chemical Properties of Tigernut (Cyperus esculentus L.) Tuber Oil

In this study, physico-chemical properties of raw and roasted tigernut oils extracted by two different solvents were determined. Peroxide values of raw and roasted tigernut oils extracted by petroleum ether and n-hexane solvents changed between 0.83 and 0.91 meqO2/100g to 1.57 and 1.63 meqO2/100g, respectively. While oleic acid contents of raw tigernut oils extracted by petroleum ether and n-hexane are determined as 66.83 and 67.47%, oleic acid contents of roasted tigernut oils extracted by petroleum ether and n-hexane were determined as 67.08 and 68.16%, respectively. The highest δ-tocopherol content was found in raw tigernut oil extracted by petroleum ether (54.91 mg/100g), while the lowest level is determined in roasted tigernut oil by n-hexane (50.77 mg/100g). As a result, the fatty acid profiles of roasted tigernut oil extracted by n-hexane were higher compared to results of raw tigernut oils extracted by petroleum ether (p < 0.05).