Food Technology
Yazdan Moradi; Mansoreh Ghaeni; Haleh Hadaegh
Abstract
Introduction
Seaweeds contain a high amount of protein, essential amino acids, vitamins, minerals, unsaturated fatty acids such as arachidonic acid, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), natural pigments, macro and micro nutrient compounds. Microalgae Spirulina (Spirulina ...
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Introduction
Seaweeds contain a high amount of protein, essential amino acids, vitamins, minerals, unsaturated fatty acids such as arachidonic acid, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), natural pigments, macro and micro nutrient compounds. Microalgae Spirulina (Spirulina platensis) is a species with high nutritional value. About 60% to 70% of the dry weight (Spirulina platensis) is protein, which has all the essential amino acids. This is a cyanobacterial microalga that is cultivated all over the world and used as a supplement in the human diet in the form of tablets, powder and cookies, bread, salad and soup. Several studies have been conducted in the field of investigating the effect of microalgae addition in food products. The purpose of the current research was to investigate the effect of this microalgae powder on sensory, physical, protein and iron properties of three different products of bulk bread, cake and layered sweets with different formulations.
Materials and Methods
Spirulina microalgae dry powder in 0.25%, 0.5%, 0.75%, 1% and 1.25% was added to the formula of three products: bulk bread, layered pastry, and cake. From each product, a sample without microalgae powder was also prepared and considered as a control. The treatments were evaluated in terms of sensory, color, texture, protein and iron content. Sensory evaluation was carried out by 30 panelists using 7 hedonic points to evaluate the color, flavor, texture, smell and overall acceptance. The color of the surface of the samples was done with a Minolta Chroma Meter (CR-300 Minolta Japan). The results calculated based on L* (whiteness/darkness), a*(redness/greenness) and b*(blueness/yellowness). Hardness of samples was measured with Texture Analyzer TA-XT2 (Stable Micro Systems, Surrey, England) and P/0.5 cylindrical probe (12.5 mm diameter) with 30 kg load cell. Protein of the samples was measured by Kjeldahl method and the amount of iron was measured according to the standard method of AOAC 999.11. All analyses were performed in three repetitions and one-way ANOVA and Tukey's test were used to compare the means.
Results and Discussion
The results showed that the behavior of spirulina microalgae in changing the characteristics of the three products is different, and this difference is especially significant in sensory characteristics. The addition of spirulina microalgae increased the amount of protein and iron in different treatments. This increase for protein in bread, cake and sweets was about 1, 0.6 and 1.2 percent, respectively. Also, the amount of iron in treatments containing microalgae in bread, cake, and layered sweets was 4, 5, and 3 mg/kg, respectively. Spirulina microalgae is basically known as an aquatic plant with high protein and iron. The microalgae used in this research contained a high amount of protein (67.97%) and 29.5 mg/100 grams of iron, so adding this microalga to the samples increased the amount of protein and iron. Sensory evaluation of the samples showed that all three products had an acceptable acceptance score. However, in comparison among the three products of bread, cake and layered sweets, bread had a lower score than the other two products. The instrumental analysis of L*, a*, b* color indices showed that the increase of spirulina caused green color in the treatments and this color change is more significant in the bread sample. Also, the results of texture analysis showed that the addition of spirulina reduces the hardness of samples containing spirulina. It can be concluded that spirulina microalgae can be used to improve texture, color, and also increase the amount of protein and iron in products.
Mohammad Noshad; Abbas Mirzaei; Sahar Asgharipour
Abstract
In this study, the fuzzy hierarchical analysis (FAHP) and TOPSIS methods was used to select the best formulations of gluten-free baguette contain modified quinoa flour (QM). For this purpose, two criteria, namely physical and chemical properties (with sub-criteria of texture, taste, flavor, color, porosity, ...
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In this study, the fuzzy hierarchical analysis (FAHP) and TOPSIS methods was used to select the best formulations of gluten-free baguette contain modified quinoa flour (QM). For this purpose, two criteria, namely physical and chemical properties (with sub-criteria of texture, taste, flavor, color, porosity, moisture, ash and mineral content, fiber content and antioxidant activity) were used to evaluate the best formulation of gluten-free of baguette. Incorporating QM from 0 to 15% increased moisture content, fiber content, hardness, antioxidant activity, a* value, Fe+2 and Ca+2 content and decreased L* and b* values. Results of FAHP-TOPSIS method showed the chemical properties have a relatively higher importance compared to the physical properties of the product and the highest importance degree of product quality evaluation is for fiber content and antioxidant activity with a final weight of 0.271 and 0.239, respectively. Also, from the experts’ point of view and based on the sub-criteria, baguette containing 10% QM with a proximity index of 0.871 was selected as the best formulation.
Raza Bataghva; Massoumeh Mehraban Sangatash; Ahmad Ehtiati
Abstract
Introduction: Hypertension is the result of angiotensin converting enzyme (ACE) activity in the vessel wall membrane. This enzyme converts angiotensin I to angiotensin II which results in vessel wall stiffness and an increase in blood pressure. Inhibition of ACE activity is a therapy for hypertension. ...
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Introduction: Hypertension is the result of angiotensin converting enzyme (ACE) activity in the vessel wall membrane. This enzyme converts angiotensin I to angiotensin II which results in vessel wall stiffness and an increase in blood pressure. Inhibition of ACE activity is a therapy for hypertension. In addition to synthetic inhibitors, some bioactive peptides (which are the products of protein proteolysis) have been identified as ACE inhibitors. Bread is a widely consumed bakery product all over the world. During dough fermentation, yeast proteases hydrolyze wheat flour proteins to prepare amino acid for cell growth. Natural cereal proteases are considered to be the other sources of protease. Proteolysis produces peptides in dough, which are bake-stable and have physiological effects on human body. Soy protein is a valuable plant protein, reported to be a source of peptides with ACE inhibitory activity and can be used to induce diversity in peptide species during dough fermentation. In this study, a completely randomized factorial design was created to evaluate the effect of the type of soy protein derivative, wheat flour substitution level and fermentation time on the ACE inhibitory activity of dough bioactive peptides. Materials and Methods: Wheat flour was substituted with 3 soy protein derivatives, including soy protein isolate, extruded soy protein and soy protein hydrolysate at 5 and 10%. Moreover, fermentation time was adjusted at 30, 60 and 90 min. Dough aqueous extract was evaluated in terms of molecular weight distribution using SDS-PAGE technique. The extract was then filtered through 3KDa membrane to separate short-chain peptides (theoretically <30 amino acids). Peptide concentration was determined using UV absorbance difference. The peptide solution was tested for the degree of hydrolysis based on OPA complexation reaction and ACE inhibition activity using FAPGG as the reaction substrate at two peptide concentrations. The experiments were triplicated and data were analyzed by ANOVA and Fisher`s mean comparison test using MINITAB software. Results and Discussion: Based on the SDS-PAGE pattern, it was observed that samples had a high level of low molecular weight peptides fraction were those enhanced with extruded soy proteins and soy protein hydrolysate. This results indicated that the addition of soy protein derivatives led to a higher content of short-chain peptides compared with wheat dough. The results also showed that all the examined variables, i.e. the type of protein, substitution degree and fermentation time, significantly affected the degree of hydrolysis and ACE inhibition activity of the separated peptides. The maximum degree of hydrolysis was observed in samples with soy protein hydrolysate- which was expected to have greater peptides diversity. This might be the reason for the higher ACE inhibition activity observed for these samples. Addition of Soy protein extrudate resulted in a higher degree of hydrolysis compared with soy protein isolate revealing that the extrusion technique caused to increase the protein susceptibility to proteolysis during fermentation along with the higher content of broken amino acid chains. The higher wheat flour substitution level resulted in a higher degree of hydrolysis, while in the case of ACE inhibitory activity, it was not significant. Overall, longer fermentation time increase the degree of hydrolysis, but led to lower ACE inhibition activity, probably due to active peptides hydrolysis. Wheat flour itself had a high level of ACE inhibition activity at the shortest fermentation time, compared with composite flours, while this activity was reduced at extended fermentation time. IC50 was the highest for the samples containing soy protein hydrolysate, surely a benefit from the initial proteolysis. In conclusion, the wheat flour substitution with 5% soy protein hydrolysate substitution,would lead to reasonable ACE inhibition activity and is suggested for bread formulation with hypertension lowering effect. It also needs more research to be done in order to evaluate substitution degrees lower than 5%, because it was observed that peptides diversity was more important than high hydrolysis degree. Overall, soy protein extrusion enhanced proteolysis and short-chain peptides production during fermentation which is a better option compared with isolated soy protein.
