Search

Abstract Background Because humans lack α-galactosidase, foods containing certain oligosaccharides from the raffinose family, such as soybeans and other legumes, may disrupt digestion and cause flatulence. Results Aspergillus niger NRC114 α-galactosidase was purified using protein precipitation, gel filtration, and ion exchange chromatography steps, which resulted in a 123-fold purification. The purified enzyme was found to be 64 kDa using the SDS-PAGE approach. The optimum pH and temperature of the purified α-galactosidase were detected at pH 3.5 and 60 ºC, respectively. The pure enzyme exhibited potent acidic pH stability at pH 3.0 and pH 4.0 for 2 h, and it retained its full activity at 50 ºC and 60 ºC for 120 min and 90 min, respectively. The enzyme was activated using 2.5 mM of K+, Mg2+, Co2+, or Zn2+ by 14%, 23%, 28%, and 11%, respectively. The K m and V max values of the purified enzyme were calculated to be 0.401 µM and 14.65 μmol min−1, respectively. The soymilk yogurt showed an increase in its total phenolic content and total flavonoids after enzyme treatment, as well as several volatile compounds that were detected and identified using GC–MS analysis. HPLC analysis clarified the enzymatic action in the hydrolysis of raffinose family oligosaccharides. Conclusion The findings of this study indicate the importance of A. niger NRC114 α-galactosidase enzyme for future studies, especially its applications in a variety of biological fields.

Abstract Background α-Galactosidase is widely distributed in plants, microorganisms, and animals, and it is produced by different fungal sources. Many studies have confirmed the valuable applications of α-galactosidase enzymes for various biotechnological purposes, like the processing of soymilk. Results Aspergillus niger NRC114 was exploited to produce the extracellular α-galactosidase. One factor per time (OFT) and central composite design (CCD) approaches were applied to determine the optimum parameters and enhance the enzyme production. The CCD model choices of pH 4.73, 1.25% mannose, 0.959% meat extract, and 6-day incubation period have succeeded in obtaining 25.22 U/mL of enzyme compared to the 6.4 U/mL produced using OFT studies. Treatment of soymilk by α-galactosidase caused an increase in total phenols and flavonoids by 27.3% and 19.9%, respectively. Antioxidant measurements revealed a significant increase in the enzyme-treated soymilk. Through HPLC analysis, the appearance of sucrose, fructose, and glucose in the enzyme-treated soymilk was detected due to the degradation of stachyose and raffinose. The main volatile compounds in raw soymilk were acids (45.04%) and aldehydes (34.25%), which showed a remarkable decrease of 7.82% and 20.03% after treatment by α-galactosidase. Conclusions To increase α-galactosidase production, the OFT and CCD approaches were used, and CCD was found to be four times more effective than OFT. The produced enzyme proved potent enough to improve the properties of soymilk, avoiding flatulence and undesirable tastes and odors. Graphical Abstract

Introduction. Biscuit is a mass-consumption product worldwide. As biscuit contains low amount of protein, it can be fortified with protein-containing raw materials. In the present work, we fortified biscuit with kishk, an Egyptian dairy product, and evaluated changes in its physicochemical properties and volatile compounds. Study objects and methods. We analyzed biscuit from wheat flour (control sample) and biscuit form wheat flour with 10, 20, 30, 40, and 50% of kishk (experimental samples). The experiments were carried out by using standard methods. Results and discussion. The fortified biscuit samples showed higher lightness (L*) values than control. The antioxidant activity in the biscuit increased with the increasing amount of kishk. Aldehydes were the main volatile compounds in all the biscuit samples, followed by sulfur-containing compounds and alcohols. The predominant aldehyde was benzldehyde. However, kishk in amounts more than 20% affected adversely the aroma, taste and texture, as well as volatile compounds of the biscuits. Both the control and fortified with kishk biscuits contained an increased amount of total phenolic compounds. Based on sensory evaluation and volatile analysis, the most acceptable amount of kishk for fortification of biscuit was 10%. Conclusion. Fortification of biscuit with Egyptian kishk enhanced its protein, fat and fiber, as well as antioxidant activity at all levels of fortification with no significant effect on appearance and color. Further studies are needed to evaluate storage conditions and shelf life of biscuits with kishk.

Fatigue and rapid exhaustion are common complaints among construction workers, as a result of high-effort levels, physical overexertion, weather and long physically demanding work hours. This study aimed to fortify cloudy apple juice with riboflavin (vitamin B2) to evaluate changes in chemical composition, antioxidant activity and volatile compounds in the fortified juice and to study its effect on the volunteer construction workers complaining of fatigue resulting from demanding physical duties. Analysis of volatile compounds in the fortified cloudy apple juice using Gas Chromatography and Gas Chromatography-Mass Spectrometry identified thirty-four volatile compounds including esters, alcohols, aldehydes and acids. The most predominant volatile compounds were alcohols followed by esters in both the control and fortified samples. We studied the effect of the supplementation of riboflavin-fortified cloudy apple juice versus conventional cloudy apple juice on the anthropometric parameters, the scores of two fatigue questionnaires (Checklist Individual Strength and Fatigue Severity Scale) and antioxidants biomarkers among young Egyptian male construction workers. This study revealed that consumption of 1.3 mg of riboflavin-fortified cloudy apple juice per day for twenty-eight days significantly improved their metabolism, with a decrease in mean body fat percentage and an increase in body muscle mass without statistically significant differences, the fortified juice significantly improved the fatigue questionnaires' scores. Moreover, the fortified supplement had a substantial change in antioxidant activity; there was significant increase in the plasma total antioxidant capacity (+74.19 %change) and catalase enzyme (+54.65 %change) with a significant decrease in the serum malondialdehyde level (−53.78 %change). When compared to the administration of conventional cloudy apple juice, although there was a significant decrease in serum malondialdehyde level (−4.63 %change) at the end of the study, only the subjective fatigue subscale of the CIS fatigue score significantly decreased among the construction workers (−24.61 %change). It could be concluded that vitamin B2 fortified-cloudy apple juice was effective in the reduction of fatigue and exhaustion in the study's subjects.

The aim of the present research was to investigate the chemical composition, antioxidant and anti-tumor effects of Cordia dichotoma fruit pulp extract “CDFP-extract”. Day after intraperitoneal inoculation of Ehrlich ascites carcinoma (EAC) cells in mice, CDFP-extract was administered orally at 500 mg/kg body weight (equal to 0.10 of determined LD50) for ten consecutive days. CDFP-extract contains 112.71 ± 8.40 mg gallic acid/g, 69.76 ± 4.18 mg quercetin/g, 25.65 ± 1.80 mg catechin/g, 70.90 ± 2.92 mg total alkaloids/g extract. The high-performance liquid chromatography (HPLC) analysis for sugar determination showed that glucouronic acid was the main compound (34.08%) followed by sucrose, glucose, and fructose by 25.61%, 11.82%, and 8.95%, respectively. The gas-liquid chromatography (GC) and GC‐MS of the fruit showed that the presence of 19 volatile compounds were identified. The main constituents of the extract were bornyl acetate, α-terpineol, linaly butyrate, and α-phellandrene. The CDFP-extract showed a powerful effect in scavenging superoxide radicals and chelating metals ions as well as high reduction capability and total antioxidant capacity, dose-dependent manner. On the other hand, the viable Ehrlich cell count and solid tumor weight were significantly reduced by administration of CDFP extract and it increased non-viable cells. The CDFP-extract ameliorated all hematological parameters, this amelioration reflected on increasing median survival time and significant increase (p

The present study aimed to evaluate the effect of various bran sources, including wheat, barley, and rice, on the quality and volatile compounds of Egyptian ‘balady’ bread (Fino). The protein, fat, and total carbohydrates content of the studied brans ranged from 8.49 to 14.16%, 2.16 to 8.12%, and 34.38 to 85.06%, respectively. The mi- neral composition and colour parameters of the brans were also evaluated. The substitution of wheat flour with 10%, 20%, and 30% of different brans resulted in decreased loaf volume and specific volume, and increased loaf weight. A significant decrease in colour parameters (L, a, and b) of the bread crust and crumb were observed in all the sam- ples. The addition of bran at three concentrations showed a remarkable increase in the total phenolic content of the bread samples, compared to the control. The antioxidant activity of the bread samples fortified with brans showed the following order: RB (rice bran) > BB (barley bran) > WB (wheat bran), as determined by the DPPH and β-carotene assays. Thirty-six volatile compounds identified in the bread samples using GC-MS included 5 alcohols, 6 pyrazines, 2 acids, 9 aldehydes, 5 ketones, 3 esters, and 6 sulphur-containing compounds. Alcohols were the predominant vola- tile constituents accounting for 58.3; 61.57; 59.08; and 56.15% in the control and in the bread samples prepared with bran from rice, barley, and wheat, respectively.

The effect of various thermal treatments (electric oven, microwave) and g-irradiation at three doses (6, 8 and 10 KGy) on the composition of volatile and non-volatile of anise essential oil and also their antioxidant properties were considered. The hydrodistilled oil (HD) of control and treated samples were subjected to gas chromatography–mass spectrometry (GC/MS) analysis. The volatile profile of raw HD oil of anise consisted mainly of transe-anethole (79.68%) followed by hexahydrofarnesyl acetone (6.95%), para-anisaldehyde (5.49%); g-himachalene (2.53%) and estragole (0.76%). Although the effect of roasting didn’t cause significant changes in the total yield of major compounds of HD anise oil which are phenylpropanoid derivative (transe anethole , para-anisaldehyde, cis-anethole and estragole (=methylchavicol), it is found that gamma irradiation revealed the same behavior at the 10 KGy irradiated sample but decrease the total yield of these compounds in 6.8 KGy irradiated sample compared to control one. also the thermal and g- irradiation caused drastic increase in the total yield of sesquiterpenes whereas decreased oxygenated compounds in all samples under investigation compared to control one. Such changes affected the antioxidant activity of the treated samples 1.1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging as well as β-carotene bleaching test against butylated hydroxy toluene (BHT). The strongest effect of reduction of DPPH radical as well as the highest inhibiting effect of the oxidation of linoleic acid and the subsequent bleaching of β-carotene was by 8 KGy irradiated sample which comprised (84.57%±1.43); (85.21% ± 0.12) respectively, in comparison to BHT (98% ± 0.0) at the same concentration 30 µg/mL besides all samples under investigation revealed high antioxidant activities due to their high content of phenylpropanoid and oxygenated compounds. These confirmed by total phenolic content. High performance liquid chromatography (HPLC) method was used for the analysis of phenolic compounds in the selected sample. Polyphenolic compounds were analysed on C18 Reversed Phase (RP) HPLC. A total of 9 phenolic compounds were identified, the obtained results showed that the predominant compound was P-qumaric acid (43.36%) followed by ferulic acid (21.06%).