2024-03-28T17:10:11Z
https://ajfs.journals.ekb.eg/?_action=export&rf=summon&issue=3987
Alexandria Journal of Food Science and Technology
1687-3920
1687-3920
2010
7
1
Enzymatic Protein Hydrolysates of Common Carp Fish: II. Antioxidant Activity
Common carp fish were hydrolysed using papain, bacterial protease, and bovine protease. The antioxidant activity of the three hydrolysates were determined. Partial hydrolysates with different degrees of hydrolysis and peptide fractions were also examined for their antioxidant activity. Then, the hydrolysate prepared using papain enzyme was chosen for further investigation. It was added to a meat model system capable to inhibit lipid oxidation, and its Hunter Lab. colour was tested. Moreover, the effects of three drying methods on the antioxidant activity and some functional properties of the papain hydrolysate were examined. Data revealed that the three fish hydrolysates possessed antioxidant activities which were boosted to about 98% by addition of 0.5% BHT. Partial hydrolysates exhibited antioxidant activities which increased with the increase in degree of hydrolysis. The highest antioxidant activity (73.2 %) was achieved with 35.2 % degree of hydrolysis for papain hydrolysate. Results also showed that the smaller the molecular weight of the peptide fraction, the higher its antioxidant activity. Addition of papain hydrolysate to meat model system delayed oxidation. Freeze drying of papain hydrolystate maintained their antioxidant activity and functional properties.
Common Carp
enzymatic hydrolysis
Proteases
Functional properties
molecular weight
Antioxidant activity
Freeze drying
2010
06
01
1
12
https://ajfs.journals.ekb.eg/article_20171_e633c84e4d32316f9257068efd4f43cb.pdf
Alexandria Journal of Food Science and Technology
1687-3920
1687-3920
2010
7
1
Effect of Some Technological Practices on Solanine in Potato Tubers
The present study was conducted to determine the effect of some technological practices on solanine content in potato sticks .Data indicated that peeling process caused a significant decrease in solanine content in potato, being 14.44% and 58.25 % (on dry weight basis) when the depths of the removal peel were approximately 0.5 and 3 mm, respectively. Boiling process at 100 C° for different periods (3-9 min) did not significantly reduce the solanine content of potato sticks. Frying of potato sticks at 170 C° for 3and 6 min caused a significant decline in solanine content. The percentages of solanine reduction after frying for 3 and 6 min, were 68.79% and 75.58 % ( on dry weight basis), respectively. Soaking of potato sticks in 4% acetic acid for different periods led to a significant reduction in solanine. The reduction was10.51%, 26.61%, 32.56% and 48.93% after soaking for 15,30,45 and 60 min, respectively. Soaking of potato sticks in 4% acetic acid for 30 and 60 min then boiling for 9 min or frying for 6 min resulted in a high reduction in solanine content of potato sticks (27.44% ,50.85 %, 80.55% and 89.08%, respectively). Separation of solanine from potato sticks subjected to the aforementioned treatments by TLC confirmed the results obtained in the present study.
α-solanine
green potato
glycoalkaloids
processing
Solanum tuberosum
2010
06
01
13
20
https://ajfs.journals.ekb.eg/article_20173_c596649a2c4f69c57ef5b4b7e60834d7.pdf
Alexandria Journal of Food Science and Technology
1687-3920
1687-3920
2010
7
1
Quality of Bottled Potable Water Locally Consumed in Egypt
Eleven commercial brands of bottled potable water locally consumed in Egypt, were investigated from the chemical and physicochemical points of view. Analysis included each of the following determinations : pH value, conductivity, total dissolved solids (TDS), total hardness (TH), total alkalinity(TAC), cations (calcium, magnesium, potassium, sodium, and iron), anions (bicarbonate, chlorides, fluorides, nitrate, phosphate, silica and sulphate) in addition to 14 heavy metals (antimony, arsenic, barium, boron, cadmium, chromium, copper, lead, manganese, mercury, nickel, selenium, silver and tin).Data revealed that all samples which were analyzed twice in two different periods cope in general with the standard specifications recommended by WHO and Environmental Protection Agency (USEPA). However, laboratory values for some chemical components were different from that mentioned on labels belonging to some brands
Bottled water
pH
Conductivity
TDS
total hardness
total alkalinity
cations
anions
Heavy metals
2010
06
01
21
34
https://ajfs.journals.ekb.eg/article_20175_874bbba798e9c6da29ca454c33228fb0.pdf
Alexandria Journal of Food Science and Technology
1687-3920
1687-3920
2010
7
1
Application of Laser in Food Technology: An Overview
Lasers are now used in different areas of science and technology. They are used in food processing in particle size distribution, modifying packaging materials, disinfection, fiber optics and in machine vision system. The unique properties of laser radiation facilitate producing instruments with a high degree of accuracy and precision could be used successfully in different food quality control systems. Matrix assisted laser desorption ionization mass spectrum (MALDI-TOF-MS) has implemented in a lot of applications, in the assay of bioactive molecules, identification of bacterial cell proteins, and in the analysis of difficult proteins and verification of the gene sequence. Raman spectroscopy technique is also considered as an important laser tool for studying meat and meat products, protein isolates and plant pigments as well as, its role in detecting the adulteration is already being well known. Laser induced fluorescence methods (LIF) are now applied successfully as a system for a quality control in palm oil industry. Also, it can be coupled with other techniques like capillary gel electrophoresis (CG-LIF ) detectors for the detection of genetically modified foods and flavin contents in different food products.Laser is newly introduced in different modern microscopic techniques like confocal laser scanning microscopy (CLSM) and atomic force microscopy (AFM).
lasers- laser in food processing- matrix assisted laser desorption ionization mass spectrum (MALDI-TOF-MS)- Laser induced fluorescence (LIF) –confocal laser scanning microscopy (CLSM)- atomic force microscopy (AFM)
2010
06
01
35
24
https://ajfs.journals.ekb.eg/article_20177_194cea0b66638ad79f7d3c1a9b244779.pdf
Alexandria Journal of Food Science and Technology
1687-3920
1687-3920
2010
7
1
A New Functional Yogurt Supplemented with Ginseng
Yogurt supplemented with beneficial ingredient is mounting to corroborate the consumer perception of health. Water extract panax ginseng was used in yogurt processing to achieve different final concentrations of ginseng. The quality attributes of ginseng yogurt were determined. Total phenolic contents, DPPH·– and ABTS·+ scavenging radicals activity and the reducing ability were measured using a spectrophotometric decolorization assay and OH· scavenging activity test using ESR was an excellent target to investigate antioxidants in the fields of food and nutrition. The results showed that the optimal concentration of ginseng extract in yogurt was approximately (0.5 mg ginseng/ml yogurt) which had recorded the best scores of acceptability and quality characteristics. The DPPH·– and ABTS·+ free radicals scavenging and the Fe3+– Fe2+ transformation were found to increase significantly, while the OH· scavenging activity decreased with the yogurt containing 0.5 mg ginseng/ml yogurt. A strong positive correlation between the antioxidant activity and ginseng concentration was observed.
Antioxidant activity
Ginseng
Yogurt
Phenolic compounds
2010
06
01
43
49
https://ajfs.journals.ekb.eg/article_20180_b252723a6c396bc9e02ca9f08e042fb5.pdf
Alexandria Journal of Food Science and Technology
1687-3920
1687-3920
2010
7
1
Physicochemical Characteristics and Storage Stability of Palm Olein and Red Palm Olein
Two types of oils, namely palm olein (POL) and red palm olein (RPOL) were characterized from the physicochemical point of view and after storage in clear and amber bottles at room temperature for one year. The latter is done to assess their oxidative stability and to monitor the degradation of tocopherols, tocotrienols and carotenes during the entire storage period. Methods employed included determination of peroxide value (PV), p-anisidine value (p-AV), acid value (AV) and free fatty acids (FFA). The results have shown that there was a significant increase (P≤0.05) in each of PV, p-AV, AV and FFA for both POL and RPOL during the storage period for 6 and 12 months. Moreover, there was a significant decrease (P≤0.05) during the period of storage in total tocopherols and tocoterienols as well as in carotenes for both POL and RPOL. Slight changes in fatty acid composition was observed for both POL and RPOL during storage for 12 months, no significant differences could be observed in this regard during the entire period of storage. Red palm olein exhibited higher storage stability than palm olein. Storage of POL and RPOL in amber bottles was superior in terms of maintaining storage stability of oils as compared to their clear counterparts.
2010
06
01
51
59
https://ajfs.journals.ekb.eg/article_20181_a84aab9f3005ec1c926bceec11bc00ea.pdf