Journal      [Total: 987 ]

Comparative Study of Vegetable Oils Oxidative Stability using DSC and Rancimat Methods

Rania Mohamed el meselhy, 2021

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COMPARATIVE study was carried out to evaluate and compare the oxidative
stabilitystability of vegetable oils (olive, corn and sunflower) in Egypt, through evaluation of
accelerated oxidation at four different isothermal temperatures (110, 120, 130, 140 °C) using
two different instruments: a differential scanning calorimeter (DSC) and a Rancimat instrument,
taking into account the physicochemical quality characteristics and relationships between
oxidative stability and fatty acid composition of oils. The Rancimat instrument was set at the
four different isothermal temperatures with an air flow 20 L/h and measures the induction
period (IP) of the selected oils. The differential scanning calorimetry (DSC) technique involved
accelerated oxidation of oil samples in an air flow of 60 ml/min in DSC cell set at four different
isothermal temperatures. A rapid increase in evolved heat was observed with the appearance of
a sharp exothermic curve during initiation of the oxidation reaction. From the resulting
exothermic curve, the onset of oxidation time (To) was determined graphically by the DSC
instrument. There was an excellent correlation (p<0.0001) found between DSC (To) values and
Rancimat (IP) measurements where the Pearson correlation coefficient (>0.98) between the two
methods with coefficient of determination (R2 >0.89) for DSC independent of the vegetable oil
source, imply that DSC can be recommended as an alternative appropriate objective method for
assessing the oxidative stability of vegetable oils because of its simplicity, absence of toxic
chemicals, small amount of sample and time-saving nature and could be easily used for routine
analysis in oils and fats industry.
Keywords: Vegetable oils, Oxidative stability, DSC, Rancimat, Comparative study


The Bacterial Lethal Effect of Gaseous or Liquid CO2 in Raw Milk

Baraka Abdelsalam Gomaa, 2021

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The consumer demands for high-quality, minimally-processed products that are microbiologically safehave been increased. Raw skim milk or pathogenic bacteria-inoculated sterilized milk was treated withgaseous or liquid (subcritical) CO2at different levels and stored at 4°C for 7 days.The bacterial reductionperformed by gaseous or liquid (subcritical) CO2, as nonthermal method, at different levels in raw milkwas compared to those of achieved by laboratory thermal pasteurization. The counts of standard platecount (SPC), coliforms and psychrotrophic bacteria were determined at 1, 3, 5 and 7 days of storageperiod in raw milk treatments and pasteurized milk. The pathogenic bacterial counts were determinedin inoculated sterilized milk during storage period. Changes in the pH values and sensorial propertiesof raw skim milk treated with different levels of gaseous or liquid CO2during storage at 4°C wereevaluated. The results showed that the SPC reduced till the 5th day of storage period with liquid CO2 atdifferent levels, while the SPC of control (without adding CO2) and gaseous CO2 treated raw milktreatments increased with prolonging storage period but the SPC growth rate of gaseous CO2 treatedraw milk treatments was lower than those of control allover storage period. The coliforms and psychrotrophic bacteria of liquid CO2– treated raw milks were lower than those of treated with gaseousCO2 along storage period. The liquid CO2 (28.17 mM) treated raw milk showed the absence of coliformsallover storage period and almost similar low counts of SPC and psychrotrophic bacteria to those of
pasteurized milk. The counts of different studied pathogenic strains inoculated in sterilized milk
declined with increasing liquid CO2 level and prolonging storage period. The counts of E. coli (twostrains) lowered, while S. aureus and B. cereus slightly increased with gaseousCO2. The pH slightlydecreased with increasing gaseous or liquid CO2levels and storage period. Off odors and coagulationare not recorded for liquid CO2 - raw milk treatments along storage period. Hence, the liquid CO2(28.17mM) can be used as effective method of storing bulk raw milk and as nonthermal method formilk pasteurization.


Nano-encapsulated Iron and Folic Acid-Fortified Functional Yogurt Enhance Anemia in Albino Rats

Wedad El-Kholy, 2021

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Iron deficiency anemia (IDA) is a major health concern in developing countries, and
these see an increased incidence in pregnant women and children in particular. The
contribution of dairy products as natural products in drug delivery approaches is inspiring.
This study aimed to analyze the application of iron (Fe) and folic acid (FA) bovine serum
albumin-nanoparticles (BSA-NPs) as anti-anemic pharmacological agents that fortify
stirred functional yogurt (SFY), comparing these with a plain control and SFY fortified
with Fe and FA in free forms. The physicochemical, cytotoxicity,microbiological, viscosity,
oxidative interactions,microstructural, sensorial analyses, and bioavailability properties of
IDA-induced Albino rats were examined. The Transmission Electron Microscope (TEM),
Zetasizer, and Scan Electron Microscope (SEM) were applied. Nanocapsule-fortified
SFY showed an enhanced apparent viscosity, water-holding capacity, microstructure,
least lipid oxidation, and overall sensorial acceptability. Feed that included Fe + FA
nanocapsule-fortified SFY (G6) succeeded in restoring hemoglobin (16.53 gdL?1), iron
(109.25 ?gdL?1), ferritin (33.25 ?gdL?1), and total protein (8.6 gdL?1) at the end of
the 4-week feeding period, with significant competition revealed in calcium and zinc
absorbance. Nanocapsule-fortified SFY showed no adverse effects or architectural
alterations in the liver, kidney, or spleen, as indicated by biochemical and histological
examinations. Bovine serum albumin-nanoparticles (BSA-NPs) of iron (Fe) and folic
acid (FA) can be recommended as anti-anemia supplements in different functional
food applications.
Keywords: anti-anemia, natural products, bioavailability, nano-encapsulated Fe and FA, food supplements, stirred
functional yogurt
Iron deficiency anemia (IDA) is one of the top 20 risk factors for the global distribution of disease
burden. TheWHOis working with the Egyptian government to addressmajor challenges due to the
prevalence of IDA, which is found


Effect of different treatments on nutritional value of lima bean (Phaseolus lunatus) and its utilization in Biscuit manufacture

SAHAR ABD EL-WAHAB El-Gohery, 2021

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Physical properties, chemical composition, minerals content, amino acids profile and anti-nutritional factors i.e. phytic acid, tannins and trypsin inhibitor of lima bean seeds (Phaseolus lunatus) which newly cultivated in Egypt were investigated. Addition to study the effect of common processing methods (soaking, cooking, roasting, and dehulling) on the chemical composition, minerals content and anti-nutritional factors of lima bean seeds in order to be used in biscuit preparation. Results showed that protein content was significantly (P ? 0.05) increased in dehulled lima bean (27.06%) compared to raw lima bean (26.02%). All processing methods significantly (P ? 0.05) increased Soluble Dietary Fiber (SDF), however soaked seeds contained the highest significant Total Dietary Fiber (TDF) (30.18%) and Insoluble Dietary Fiber (IDF) (22.15%). Raw lima bean was superior in calcium, iron, magnesium, sodium, potassium, copper, and zinc compared with all processed samples. Raw lima bean had a higher content of all essential amino acids, except methionine compared to wheat flour of 72% extraction rate. The effect of different processing methods used in this study on lowering phytic acid and tannins, was arranged in the following significant (P ? 0.05) order: dehulling > cooking> roasting > soaking. Trypsin inhibitor was completely eliminated by cooking and dehulling treatments. Results showed that no significant differences (P ? 0.05) were found in appearance, color, texture and overall acceptability of biscuits substituted with 30% raw or processed lima bean and between control biscuit (100% wheat flour). The diameter, spread ratio, chemical composition (protein, ash, crude fiber, SDF, IDF and TDF) and minerals were significantly increased in all substituted biscuits compared to control biscuit. Improvement in the essential amino acid profile of raw lima biscuit was observed with higher values of essential amino acids, chemical score (CS), and biological value (BV). This study recommended the use of lima bean in preparing biscuits at 30% replacement to enhance the nutritional composition of biscuits with acceptable sensory properties.


Quality aspects for high nutritional value pretzel

SAHAR ABD EL-WAHAB El-Gohery, 2020

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The present study was carried out to improve the nutritional value of pretzels made from wheat or barely flour by adding chickpea or sweet lupine powder at different percent of replacement. Chemical composition of raw materials indicated that sweet lupine and chickpea powder contained higher amounts of protein, fat and crude fiber (28.45, 26.05% & 7.53, 8.08% & 7.57, 4.86%, respectively) compared with wheat and barley flour. Wheat and barley pretzels replaced by 40 % chickpea powder or 20 % sweet lupine powder indicated significant (P ? 0.05) improvement in different sensory characteristics. Control barley pretzel had higher total essential amino acids content (41.86 g/100 gm protein), followed by barley pretzel replaced by 20% sweet lupine powder (41.25 g/100 gm protein). The protein quality indicated increase of biological value (BV) and protein efficiency ratio (PER) for pretzel replaced wheat or barley flour by chickpea or sweet lupine powder. All pretzel samples replaced wheat or barley flour by chickpea or sweet lupine powder had higher content of minerals than control samples. Barley pretzel samples had higher content of magnesium, potassium, calcium, iron and zinc compared with wheat pretzel samples. Wheat and barley pretzel samples replaced by chickpea or sweet lupine caused an increase of total phenolic and total flavonoids contents. Antioxidant activity (DPPH%) showed that barley pretzels had the highest antioxidant activity, while wheat pretzels showed the lowest activity


Utilization of Yellow Corn in Preparing High Nutritional Value Gluten-Free Noodles

Ghada Elfauomy, 2020

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Abstract: The present study aimed to produce gluten-free noodles from yellow corn grits, rice flour and chickpea
powder blends and then evaluate their sensory, nutritional and technological characteristics. Yellow corn grains were
ground and sieved to obtain the grits at three particle size (? 200, 200–350 and 350–450 ?m). The highest protein
content was observed at particle size 200-350 and 350-450 ?m and the particle size 200-350 ?m had the highest value
of water hydration index (WHI) which are needed for noodles making. Consequently, noodles were formulated using
yellow corn grits (200-350?m), 10% chickpea powder and different substitutions of rice flour (10, 20, 30, 40 and 50%).
Noodles contained 40% rice flour were closed to semolina noodles with respect to sensory characteristics. Noodles with
10% rice flour showed high values of protein, fat, Ca, Zn and ?-carotene and low total carbohydrates content. The
hardness and cohesiveness of noodles were increased by increasing the rice flour percentage. The gluten-free noodles
made with 40% and 50% rice flour as yellow corn grits substitution possessed the highest cooking time. Increasing the
rice flour percentages in the noodles formulation lead to increase cooking weight and swelling percentage and
decreasing the cooking loss and protein loss percentages. Gluten-free noodles contained 50% yellow corn grits, 40%
rice flour and 10% chickpeas powder showed the highest overall acceptability. It could be concluded that using of
yellow corn grits, rice flour and chickpea powder in gluten-free noodles formulation are suitable for celiac disease
individuals.
Keywords: Corn grits, rice flour, chickpea powder, gluten-free, texture profile, sensory characteristics, cooking quality


Influences of Biological Control on Damping Off Diseases of Faba beans as well as Physico-Chemical and Technological Properties

Ghada Elfauomy, 2020

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Faba bean seeds are the most important legumes in terms of consumption, for its positive nutritional properties and the most important diseases of Faba bean seeds are damping off. The field experiments was carried out during the 2017- 2018 and 2018-2019 seasons to study the effect of the biocontrol agents as well as Rizolex T on the incidence of Faba beans damping off disease. The growth parameters, yield and its quality parameters of Faba bean plants were also, studied. The cultures of Paenibacillus polymyxa, Pseudomonas fluorescens and Bacillus megaterium bacteria and the Trichoderma viride, Trichoderma. harzianum fungi were used. The results exhibited that, the highest percentage of preemergence damping off reduction, the maximum plant height and the maximum seeds weight per plant were recorded with Rizolex T and P. polymyxa followed by B. megaterium and T. harzianum treatments. Significantly increases in the percentage of survived plants compared with the control were found in all treatments. Number of branches, and number of pods per plants were the highest in the Rizolex T treatment. Quality parameters of the faba bean crops resulted, such as protein, protein digestibility and minerals (Fe and Zn), as well as, total flavonoid and antioxidant activity evaluations were significantly increased in P. polymyxa, B. megaterium followed by Rizolex T compared with control samples. Technological evaluation of density, ratio between cotyledons and seed coats, as well as, water absorption, hydration coefficients and swelling coefficients after soaking and cooking were studied and showed high levels in Faba beans treated with P. polymyxa, B. megaterium and Rizolex T. Also, high level of cookability (stewing) and sensory characteristics were detected in Faba beans treated with P. polymyxa, B. megaterium and Rizolex T compared with other treatments and control.
Keywords: Faba beans, Damping off, Biocontrol agents, Rizolex T, Hydration coefficients, Swelling coefficients


Evaluation of Pies Containing Licorice Roots (Glycyrrhiza glabra L.) Extracts

Ghada Elfauomy, Hinar Selim, Mona Mohamed aly, 2020

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Licorice roots (Glycyrrhiza glabra L.) are an important medicinal plant, and have numerous uses. Two extractors (water and ethanol) were used to extract the phytochemicals from licorice roots. Antioxidant and antimicrobial activities of such extracts were evaluated. Three different concentrations (100, 250 and 500?g/ml) of water and ethanolic extracts were used to investigate inhibition zone and properties against some bacteria strains (Staphylococcus aureus, Salmonella typhimurium, Bacillus subtilis and Escherichia coli) and fungi (Asperigllus flavus, Asperigllus niger and Penicillum chrysogenu). The present results indicated that ethanolic extract exhibited the highest antioxidant activity (AOA) at 600?g/ml. The AOA (IC50) for ethanolic and water extracts was 110 and 212 ?g/ml, respectively. Total phenols of water and ethanolic extracts was 21.01 and 45.24 mgGAE/gDW, respectively. The results of HPLC analysis fractionations showed that both water and ethanolic extracts contained a high level of pyrogallol, coumarin and catechin. The exist major flavonoids were hisperdin and quercetrin in the ethanolic extract. It was revealed that the antimicrobial activity of the ethanolic extract was higher than of the water extract. Three levels of ethanolic licorice extract were used in pie preparing. The effect of addition licorice ethanolic extract (100, 200 and 300 mg/100g wheat flour) in preparing pies were evaluated and the results cleared that, improve in physical properties at 200 and 300 mg/100g compared with control. Taste, volume and crumb color of pies were improved at 200 and 300 mg licorice extract. Addition of ethanolic licorice extract at 200 and 300 mg successfully extended the microbiological shelf life up to 12 days compared with 6 days for control.
Keywords: licorice roots, aqueous extract, ethanolic extract, antioxidant, antimicrobial, bakery products, shelf life.


Utilization of inulin extracted from chicory (Cichoriumintybus L.) roots to improve the properties of low-fat synbiotic yoghurt

Wedad El-Kholy, 2020

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The present study was aimed to extract and purify inulin from chicory roots and evaluate the physicochemical
properties and functional groups of the purified inulin for comparison with those of standard chicory inulin.
This study investigated the impact of various inulin concentrations on of low-fat yoghurt quality, including
physicochemical, microstructural, textural and sensory properties, the impact of inulin as a prebiotic on the
growth and viability of synbiotic yoghurt. The characteristics of the microstructurewere investigated by scanning
electron microscopy (SEM). For functional group detection, Fourier transform infrared (FTIR) spectroscopy was
used. For separate and quantify of inulin content determination were performed on a high-pressure liquid
chromatography combinedwith refractive index detector (HPLC-RID)method. The evaluation of inulin extracted
from chicory roots revealed a white powder with a natural taste and no off flavours. Inulin was less sweet than
sugar (sucrose) and was moderately soluble in water, colourless, and clear to hazy, with a pH of 5.84. Chicory
inulin showed a high content of reducing sugars (4.9%). The addition of inulin at 1% enhanced the
microstructural, textural and sensory properties of yoghurt compared to those of the control, and this yoghurt
can be considered a functional synbiotic product because it contains both probiotics (N6 log cfu g?1) and
prebiotics. The inulin addition to the probiotic yoghurt improved the viability of S. thermophilus, L. bulgaricus, L.
acidophilus and B. bifidumduring storage. Overall, low-fat synbiotic yoghurt containing 1% inulin was comparable
in its performance features to the full-fat probiotic yoghurt control.
© 2018 Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http


Effect of Fortification Breadsticks with Milk Thistle Seeds Powder on Chemical and Nutritional Properties

Adly saad, 2020

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ABSTRACT
This work aim to verify the importance of milk thistle seed powder (MTSP) as a medicinal plant and effect of fortification wheat flour (WF) with MTSP on chemical and nutritional properties. Therefore, the chemical composition such as ether extract, dietary fiber, crude protein, vitamin C, amino acids and minerals contents were determined. Also, the antioxidative properties such as phenolic compounds and flavonoid compounds and scavenging activity on DPPH free radicals were also determined. Furthermore, the possibility to use MTSP in bread sticks preparation, where the use of MTSP as replacer of WF at different extents (4, 8 and 12%) to prepare bread sticks rich in protein and minerals, as well as organoleptic evaluation of prepared bread sticks were investigated. Results indicated that MTSP have high amount of protein (25%), ether extract (25.56%), crude fiber (29.68%), minerals content (4.55%), vitamin C (4.59 mg?g), flavonoids (20,65 mg/g), and phenolic compounds (40.33 mg as Gallic /g) (antioxidants) which, could be used as alternative natural source for synthetic antioxidants in industry. The indispensable and dispensable amino acids are more abundant in MTSP protein. Sensorial evaluation of the obtained products indicated that successful replacement was 4, 8 and 12% of MTSP. So, it could be recommended to use the investigated plant seeds in bread sticks production for its nutritional concept and Antioxidative effects. Finally, the use of inexpensive available natural sources of bioactive material and incorporated to our low-cost foods for treatment or protection of our widespread disease is innovated road to produce low price therapeutic foods available to wide levels of our people.


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