Journal of Food Biosciences and Technology
Year:2018 | Volume:8 | Issue:1|Papers Count:10

Roasting is one of the widespread methods for processing of nuts and beans that significantly enhances the flavor, color, texture and appearance of the products. In this research the kinetics and modeling of soybean roasting using combined infrared-hot air system and consumption of energy were investigated. The effect of the hot air temperature (160, 180 and 200 oC), infrared powers (200, 250 and 300 W) and combined hot air temperature and IR powers (120, 140 and 160 oC- 130, 165 and 200 W) on roasting rate of soybeans were evaluated. The results showed that the effect of hot air temperature, infrared power and combined hot air temperature and IR power on the roasting rate of soybean were statistically significant and the roasting process occurred within the falling rate period. Among the five thin-layer roasting models fitted to the experimental data, the page model was the best to describe the roasting behavior. Fick’s law of diffusion was used to determine the effective moisture diffusivity, which varied between 1.727×10-9 to 4.518×10-9 m2/s. Activation energy was estimated by Arrhenius and modified Arrhenius equations as 22.0234 kJ/mol and 4.3778 kW/kg, respectively. Comparison of roasting methods showed that minimum energy was consumed in the infrared method (0.0905 kWh) and maximum energy was recorded for hot air roasting (1.752 kWh), thus infrared radiation could be considered as a promising technique for roasting of soybeans due to lower energy cost.

Barbari is traditional flat leavened Iranian bread and one of the most popular breads consumed in Iran. Barbari bread stales quite fast and its shelf life is very short. Therefore, the addition of bread improvers and anti-staling agents, such as aloe vera, is a suitable method for extending the shelf life of the bread. In the present study, the effect of aloe vera powder at 0, 1, 3, 6 and 9% (w/w based on flour) concentration on dough rheological properties, fresh bread quality and bread staling have been investigated. Dough water absorption was increased by the addition of aloe vera and 9% aloe vera had the highest effect. In all the treatments, the extensibility of dough was significantly decreased with an increase in the resting time from 45 to 135 minutes, that is probably due to the water-biding ability of aloe vera (P<0.05). The application of aloe vera resulted in increase in dough development time (DDT) but dough stability decreased. Hydrocolloid addition to the bread formulation improved the rheological properties of Barbari bread and retarded the staling process while toughness was changed in the range of 7.87-60.7 mJ.

Nowadays, milk tablets are considered favorable due to several advantages, including good taste and chewing properties, ease of transport, increased bioavailability, ease of storage, stability of active ingredients and improved functional properties. This study seeks to investigate the characteristics of fermented milk tablets in relation to its use as a beverage producing tablet. The effects of effervescent agent contents (0, 20, 40, 50, 60 %) (citric acid, tartaric acid and sodium bicarbonate) on physical and sensory properties of fermented milk tablets were evaluated. Physical properties, including weight and diameter of the tablet containing different percentages of effervescent agent (i.e.0-60 %) did not differ significantly (P≤0.05). Increasing the level of the effervescent agent (i.e.0-60%) led to hardness reduction, as well as the friability value and dissolution time of this tablet in water. Regarding the sensory properties of the fermented milky drink produced by tablets, the appearance, mouth feel and flavor acceptability of fermented milk tablets containing 40 % effervescent agent had the highest significant score (P≤0.05).

In this research, yeast-salt method was used to make flat bread dough. The yeast used for this process was Saccharomyces cerevisiae (PTCC-Code 5080), that was employed at the concentrations of 0.06% and 0.12% (w/w based on wheat flour). In order to carry out this research, a completely randomized design with three replications was used. Means were compared through Duncan's multiple range tests. The findings indicated that the increase in the yeast employed in this method, led to an increase in the degree of water uptake, dough development time, stability period, resistance and quality number as compared to the control. In addition, dough made through yeast-salt method, had a bigger area under the curve (energy), was more resistant to extensibility and had higher coefficient (correlation between resistance to stretching and extensibility) than the control. The results obtained from chemical analysis showed that samples of flat bread made through yeast- salt method contained higher moisture, protein and ash contents but had lower pH.

The objective of this study was to investigate the effect of different thermal treatments (20-100°C at five levels for 20 min) on rheological properties of basil seed (Ocimum basilicum) and balangu seed (Lallemantia royleana) gums. Power law model well described the non-Newtonian pseudoplastic behaviour of the seeds gums. The apparent viscosity of balangu seed gum was dramatically affected by the temperature and decreased from 0.015 to 0.007 Pa.s with increasing temperature from 20 to 100°C (at 97.8 s-1). Apparent viscosity of basil seed gum decreased from 0.053 to 0.022 Pa.s with increasing temperature from 20 to 100°C (shear rate=97.8 s-1). Seeds gums showed shear thinning behavior at all temperatures. The Arrhenius relationship was used to describe the temperature dependency of rheological parameters of basil seed and balangu seed gums. The activation energy of basil seed and balangu seed gums was quantified using an Arrhenius equation and increased from 4297 to 17434 J mol-1 and 2210 to 11257 J mol-1 as shear rate changed from 6.12 to 245 s-1, respectively. The flow behavior index (n), that is related to non-Newtonian behavior (pseudoplasticity), increased significantly (P≤0.05) in basil seed gum after heating, however it was decreased significantly (P≤0.05) in balangu seed gum after heating.

The use of new compounds to increase the shelf life of more perishable foods based on nanoparticles and biodegradable polymers have been developed in packaging. Chitosan (Cts) is a natural biopolymer with excellent biodegradability and nontoxicity and antibacterial effect. In this research antibacterial copper nanoparticles (CuNPs) were incorporated in the biodegradable chitosan matrix for applications as packaging materials. The properties of Cu/Cts bionanocomposites (BNCs) were studied as a function of the CuNPs concentration. Surface morphology and elemental composition of the film was investigated by scanning electron microscopy attached to EDXRF. Mechanical analysis and water vapor barrier properties of CuNPs/Cts composites were analyzed. It was observed that mechanical and water vapor barrier properties of the films were improved by the concentration of CuNPs. The antibacterial activity of CuNPs/Cts thin films were evaluated based on the diameter of the inhibition zone in a disk diffusion test against gram positive bacteria i.e., Staphylococcus aureus and Bacillus cereus and gram negative bacteria i.e., S.epidermidis and Streptococcus A. that are responsible in food deterioration, using Mueller Hinton agar at different concentration of CuNPs. The results revealed a greater bactericidal effectiveness for nanocomposite films containing 0.15mol/L of CuSO4 solution. Packages prepared from Cts/Cu nanocomposite films were used for meat packaging. The films were filled with meat and then stored at 4 ºC. Microbial stability of the meat was evaluated after 3, 7, 10 and 15 days of storage. The results showed that microbial growth rate significantly reduced as a result of using this nanocomposite packaging material.

Soya burger is one of the meat replacers with low cholesterol content and saturated fats. Regarding the gums application in food systems, the effect of adding xanthan (0, 0.4, 0.6%) and caboxymethyl cellulose gums (0, 0.4, 0.6%) on water holding capacity (WHC), cooking loss, shrinkage and sensory evaluation of soya burger have been investigated. It was found that the samples with xanthan and carboxymethyl cellulose had significantly higher (p<0.05) water holding capacity and shrinkage but lower cooking loss. Sensory analysis indicated that the samples with added mixtures of two gums (0.6+0.6 %) had the highest acceptability by the panelists. Consequently, this research showed that the addition of xanthan and carboxymethyl cellulose gums had successful results in physicochemical and sensory properties of soya burgers.

This study examines the antibacterial effects of Arum conophalloides on S. typhimurium bacteria at different temperatures (–18°, 8°, 16°, 24°, and 32°C) and time intervals (1, 2, 3, 6, 12, 24, and 48 days). This local plant was studied to determine the greatest effect caused by the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) as well as the antimicrobial effects of the extract. The Arum conophalloides essence was extracted via distillation or vapor using Clevenger hydro-distillation, using alcohol, chloroform, and water to extract the essence from Arum plant leaves (leading to three different extracts for comparison). In order to determine whether the extract used had minimum inhibitory and bactericidal effects, a microbial test method (isolate; 4, disk diffusion) was used in which two given dilutions (17, 000 ppm and 35, 000 ppm) were obtained and one of the two groups (dilutions) was selected as the control. Three groups of MIC and MBC and a control group were evaluated on plate-count agar using pour-plate technique at the designated temperatures and time intervals. Total numbers of bacterial colonies were counted. The resulting data were statistically analyzed with SPSS, with p<0.05 indicating the statistical significance. The results of the Kruskal-Wallis were only statistically meaningful for 35, 000 ppm dilution; as with the 17, 000 ppm dilution in the assumption of sphericity test, the difference in the total number of colonies was only meaningful at 18°C and on days 12 and 48, which had the lowest number of colonies (p=0.005). However, at 35, 000 ppm, the assumption of sphericity test indicated strongly the significant differences in the total number of colonies at –18°C at days 12, 24, and 48 (p=0.000) and at 16°C on day 48 (p=0.013) due to the absence of colonies at these temperatures and time points. The alcohol and chloroform extracts of different parts of the plant did not yield significant results. It might be concluded that the extracts obtained in this study have a relatively low effect concerned with MBC on S. typhimurium bacteria and based on our result, a connection can be made between Arum conophalloides extraction method and MIC, MBC.

Androgenetic alopecia is the chief type of scalp hair loss regardless of gender, causing anxiety, depression, arterial stiffness, and cardiovascular disease. The areal parts of Olea europaea (OE) and Trigonella foenum-graecum (TF), as well as the bulbs of Allium sativum (AS) are vastly used in Persian folklore for a great range of culinary and medicinal purposes. This study was an attempt to evaluate 5α-reductase (5α-R) inhibitory activity of the ethanol-based extracts of three edible plant species traditionally used in Iran. In order to measure enzyme inhibitory potential, six samples were prepared: NADPH+enzyme+testosterone+extract (n=3); enzyme blank (n=1); positive and negative controls (n=2). On the whole, AS and TF showed strong enzyme inhibitory activities. The findings indicated that the herbal extracts tested in the present study could be utilized to develop new remedies to manage testosterone-induced diseases such as androgenic alopecia.

In the present study, Persian gum, an exudate gum which secrets from the mountain almond tree (Amygdalus scoparia Spach) from two different regions is evaluated by means of chemical and instrumental analysis (fractionated by solving in water and alkaline solutions at 0.1, 0.5 and 1 M and also Smith degradation) using HPLC, 1H–NMR and 13C–NMR spectroscopy’s. The total sugar and uronic acid content of the gum are 88.70 and 10%, respectively. The results of the instrumental analyses revealed that the gum is predominantly composed of galactose and also (1®3) linked b-D–Gal p and rhamnose residues that exist at the backbone of polysaccharide where as the branches are composed of (1®6) linked b-D–Gal p and (1®) and/or (1®3) linked a-L-Ara f residues. Therefore, due to the desirable structure of Persian gum (arabinogalactane) that is similar to the other hydrocolloids, it might be employed in food products.