Food Microbiology and Biotechnology
Fred Coolborn Akharaiyi; Phebean Onosen Ozolua; Christopher Johnson
Abstract
Consumption of fruits, vegetables, and nuts is essential for human health because of their minerals, vitamins, antioxidants and dietary fibre contents. Two types of beverages were prepared (tiger nut beverage and tiger nut/beetroot beverage). 200 g tiger nut was homogenized in 1 L of sterile water to ...
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Consumption of fruits, vegetables, and nuts is essential for human health because of their minerals, vitamins, antioxidants and dietary fibre contents. Two types of beverages were prepared (tiger nut beverage and tiger nut/beetroot beverage). 200 g tiger nut was homogenized in 1 L of sterile water to prepare tiger nut beverage while 200 g of tiger nut with 20 g of beetroot to prepare tiger nut/beetroot beverage were homogenized with 1 L of sterile water. The prepared products were pasteurized at 80 °C for 5 min and left to ferment at room temperature (28±2 °C) for 4 days. The products were analyzed for chemical composition and microbial load. Results obtained showed no significant differences in the moisture, ash and protein content products. However, significant differences existed in fibre, fat and carbohydrate contents. Leuconostoc mesenteroides, Lactobacillus plantarum, Lactobacillus acidophilus, Streptococcus lactis, Saccharomyces cerevisiae, Saccharomyces exiguus, Saccharomyces stellatus and Candida pseudotropicalis were isolated from products. The number of bacteria in Tiger nut beverages increased from 0.85×103 to 1.83×107 and 0.97×103 to 1.78×107 in the Tiger/beetroot beverage. Mould and yeast counts in the tiger nut beverage increased from 0.32×102 to 1.06×104 while in the mixed product, the increase was from 0.30×102 to 1.18×104. There were no significant differences in pH and titratable acidity throughout days of fermentation. The tiger nut/beetroot beverage has high overall acceptability. The beverages could serve as a good material for the production of quality yoghurt in place of animal milk that is mostly used for yoghurt production.
Food Biophysics
Fatemeh Azarikia; Saman Abdanan Mehdizadeh
Abstract
Dehydration of Noughl, as a sugar-based confectionary product, negatively affects its texture which can be hindered by increasing relative humidity (RH) of atmosphere of storage container. In this research, glucose syrup (GS) and its mixture with salt at different ratios (8:1, 4:1 and 2:1) was utilized ...
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Dehydration of Noughl, as a sugar-based confectionary product, negatively affects its texture which can be hindered by increasing relative humidity (RH) of atmosphere of storage container. In this research, glucose syrup (GS) and its mixture with salt at different ratios (8:1, 4:1 and 2:1) was utilized as RH-modifier inside the storage container in order to prevent hardness of Noughl. The effect of RH-modifiers on moisture, hardness, area and color of samples was investigated during 30 days. Color and area changes of samples were measured using image processing. According to the findings, the lowest change in moisture content, color and area of saffron Noughls was observed when GS-salt mixture was used at the ratio of 8:1. It is found that the RH-modifier could re-increase the RH of container internal space after opening and reclosing lid of the container for 29 times. Furthermore, hardness of Noughls was hindered since the average hardness values were 32.40 and 23.38 N on zero and 30 days, respectively. However, hardness of control sample reached to 149.85 N on day 5. Based on sensory evaluation, there was no significant difference between the overall acceptability of fresh Noughls and those stored for 30 days (P<0.05). The introduced low-cost RH-modifier can be applicable for different foodstuffs to prevent dehydration.
Food Technology - Meat, Chicken, Fish and Their Products
Fereshte Bahmanyar; Seyede Marzieh Hosseini; Leila Mirmoghtadaie; Saeedeh Shojaee_Aliabadi
Abstract
The objective of this paper is to appraise the quinoa and buckwheat seeds as pseudocereals to develop new beef burgers. In this study, three different formulations were prepared: one control sample with 15% mixture of bread crumb with soy protein, and two samples with 15% quinoa flour (QB) and buckwheat ...
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The objective of this paper is to appraise the quinoa and buckwheat seeds as pseudocereals to develop new beef burgers. In this study, three different formulations were prepared: one control sample with 15% mixture of bread crumb with soy protein, and two samples with 15% quinoa flour (QB) and buckwheat flour (BB), respectively. This replacement did not make significant difference between the different formulations in most of the physicochemical characteristics including moisture content, pH value, frying properties and water activity but emulsion stability and protein content were higher in the control sample than new formulations. Based on the results of texture properties, raw control sample showed significantly harder texture but BB showed harder texture after frying. Moreover, raw quinoa burger had a higher lightness value (L*). A comparison between the QB and BB burger showed significantly increase in protein and fat content, emulsion stability and lightness of QB. In conclusion, the replacing of bread crumb and soy protein mixture by buckwheat and quinoa flours in beef burger, especially by quinoa flour did not cause significant damage to burger properties and might be a suitable strategy to produce a new functional burger with comparable physicochemical and textural properties.
Food Hydrocolloids
Mohammad Reza Salahi; Seyed Mohammad Ali Razavi; Mohebbat Mohebbi
Abstract
This study evaluated the impact of agar gum (AG) (0-0.7% w/w) on the textural, rheological, and held water characteristics of cold-set whey protein isolate emulsion filled gel (EFG). Steady shear results showed that EFGs had a shear-thinning flow behavior, and with increasing AG concentration, the consistency ...
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This study evaluated the impact of agar gum (AG) (0-0.7% w/w) on the textural, rheological, and held water characteristics of cold-set whey protein isolate emulsion filled gel (EFG). Steady shear results showed that EFGs had a shear-thinning flow behavior, and with increasing AG concentration, the consistency coefficient increased from 339.12 Pa.sn (no AG) to 951.46 Pa.sn (0.7% AG). The amplitude sweep assay illustrated that the AG level had a meaningful effect on the rheological parameters so that GʹLVE, GʹʹLVE, Gf and tF increased, and Tan dLVE decreased with an increase in the AG level. Based on the frequency sweep test, adding AG significantly enhanced the magnitudes of kʹ and kʹʹ, so that their values increased from 5311.80 and 939.90 Pa in the control to 25080.60 and 3574.90 Pa in the 0.7% AG-contained sample, respectively. Also, the parameters of the strength of the network (5380.10-25344.30 Pa.s1/z), the network extension (10.05-15.59) and the extent of departure from the Cox-Merz rule (3476.80 to 21509.44 Pa) increased directly as a result of the rise in AG content. In the composite EFG with 0.7% AG, the highest initial tangent modulus and fracture stress were recorded, which showed lower fracture strain and equal fracture energy in comparison to the control sample. Research results also showed that the held water decreased meaningfully at a high concentration of AG. These results add to the knowledge of the protein-polysaccharide interactions that can be helpful in the production of new functional foods.
Fatemeh Taheri; Asma Jafar Daghighi; Hojatollah Bodaghi; Amin Ebrahimi; Ziba Ghasimi Hagh
Abstract
Longevity of 4 Cherry tomato cultivars as the perishable climacteric fruit and the expression of ethylene biosynthesis genes (SAM1, ACS4, ACO1 and ACO4) under packaging (LDPE film) and 1-MCP plus packaging (5 µL L-1 for 48 h at 20 °C) treatments at 20 °C for 16 days were studied. The results ...
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Longevity of 4 Cherry tomato cultivars as the perishable climacteric fruit and the expression of ethylene biosynthesis genes (SAM1, ACS4, ACO1 and ACO4) under packaging (LDPE film) and 1-MCP plus packaging (5 µL L-1 for 48 h at 20 °C) treatments at 20 °C for 16 days were studied. The results of weight loss and firmness showed that there is no remarkable difference between packaging and 1-MCP plus packaging in 4 tomato cultivars, but the fluctuations of TSS and pH were more minor in 1-MC P plus packaging compared to the other treatments. Base on the physicochemical characteristics and quality maintenance, cultivars were graded from high to low durability; yellow pear, orang santa, blackberry and orange berry, respectively. The study of expression pattern of genes SAM1, ACS4, ACO1 and ACO5 in yellow pear and orange berry cultivars at storage showed that they were drastically expressed higher in control than packaging and 1-MCP plus packaging treatments. The expression level of ACO5 gene was the same in both cultivars, but the expression level of ACO1 and ACS4 genes in the yellow pear cultivar was higher than the orange berry. In contrast, the expression level of SAM1 gene in the yellow pear cultivar was lower than the orange berry. Totally, despite being deeply different in the genetic background of these cultivars, packaging and 1-MCP plus packaging treatment reduced the perishability, and improved the maintenance quality of cherry tomato fruit. Also, further molecular studies and evaluation of ethylene in these cultivars are suggested.
Food Biotechnology
Najmeh Khademi pour; Anousheh Sharifan; Hosein Bakhoda
Abstract
Astragalus fasciculifolius belongs to the genus Astragalus and the legume family. The distribution of this plant is in Southwest Asia. So far, no detailed studies have been conducted on this plant. This study tried to extract different parts of Astragalus fasciculifolius (gum, aerial parts, and roots) ...
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Astragalus fasciculifolius belongs to the genus Astragalus and the legume family. The distribution of this plant is in Southwest Asia. So far, no detailed studies have been conducted on this plant. This study tried to extract different parts of Astragalus fasciculifolius (gum, aerial parts, and roots) using two solvents of water and methanol. The extracts' content of total phenolic and flavonoid compounds and antioxidant activity (DPPH, ABST, CUPRAC, PMB, and FRAP) were evaluated, and the correlation between total phenolic compounds and antioxidant activity or Pearson test was investigated. The results showed that the methanolic gum extract had the highest antioxidant activity as well as the highest content of total phenol (22.30±1.30 mg GAEs/g extract) and total flavonoids (11.30±0.87 mg Routine (RUE)/g), which was significantly different from the other parts extracts (P≤0.05), and the correlation between total phenolic compounds and antioxidant activity was also significant (P≤0.05). According to the results, it was found that methanolic gum extract has antimicrobial activity and the MIC and MBC of Clostridium perfringens were lower than Pseudomonas aeruginosa. Based on the findings of this study, Astragalus fasciculifolius gum has the potential to be used in food, pharmaceutical, and health industries.
Food Technology - Cereal Products and Baking
Saeedeh Shahbazizadeh; Sara Naji-Tabasi; Mostafa Shahidi-Noghabi; Amir Pourfarzad
Abstract
Increasing shelf-life and nutritional value of bakery products always are important. In this research, curcumin (CUR) loaded in nanogel-reinforced hydrogel (isolated soy protein (ISP)/Sodium alginate (SA) nanogel-based cress seed gum (CSG) hydrogel) was used to improve rheological characteristics of ...
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Increasing shelf-life and nutritional value of bakery products always are important. In this research, curcumin (CUR) loaded in nanogel-reinforced hydrogel (isolated soy protein (ISP)/Sodium alginate (SA) nanogel-based cress seed gum (CSG) hydrogel) was used to improve rheological characteristics of dough and technological and organoleptic properties of Barbari bread (traditional Iranian bread). The effects of nanogel-reinforced hydrogel (at 0, 5, and 10% levels (flour basis)) with and without CUR on Barbari bread quality were investigated. The rheological properties of dough were evaluated by farinograph and extensograph analysis. The results showed that water absorption, consistency, energy and extensibility of dough increased with addition of composite hydrogels, while degree of softening 10 min after beginning reduced. Addition of hydrogel increased specific volume, porosity and hardness of the bread. The crumb lightness of CUR-composite hydrogel increased (75.51±0.06) in compared to control (69.19±0.07). Presence of 10% hydrogel composite significantly increased (a*) parameter of crust (9.96±0.13) (P<0.05). The enthalpy and endothermic peak temperature reduced due to incorporation of 10% (w/w) CUR-composite in bread. The results showed the addition of 10% CUR-composite improved the organoleptic properties of the bread and its shelf life.
Food Processing
AR. Umayal Sundari; Veeramanipriya E.
Abstract
In the present work, a forced convective hybrid photovoltaic thermal (PV-T) solar dryer assisted with an evacuated tube collector (ETC) is set up to investigate the thin layer drying of potato slices. The drying experiment is compared with the traditional sun drying method without PV-T system under the ...
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In the present work, a forced convective hybrid photovoltaic thermal (PV-T) solar dryer assisted with an evacuated tube collector (ETC) is set up to investigate the thin layer drying of potato slices. The drying experiment is compared with the traditional sun drying method without PV-T system under the meteorological conditions of Thanjavur, Tamilnadu. The initial moisture content of potato slices used for the study is 91% (wb). The drying experiment was carried out at different air temperature levels of 50, 55 and 60 °C. Nine numerical models are used to study the drying kinetics of untreated potato slices. Using IBM SPSS 23 statistical package, non-linear regression analysis was performed to estimate correlation coefficient (R2), reduced chi-square (χ2) and root mean square error (RMSE). The model developed by Midilli et al., is the most appropriate one to describe potato slices thin layer drying behavior in a hybrid dryer. The effective moisture diffusivity (Deff) determined using Fick’s second law of diffusion was found to vary from 2.12463×10-8 to 2.79233×10-8 m2/s. The activation energy (Ea) determined using the Arrhenius equation was found to be 16.4276 KJ/mol for drying of potato slices.
