Research and Innovation in Food Science and Technology
Year:2016 | Volume:5 | Issue:1|Papers Count:8

Okara is by-product of soy milk and tofu production with exclusive nutritional value and functional properties that is not sufficiently applied in food industry. The purpose of present study was optimization of sponge cake formulation with okara (0-66% of wheat flour) and kiwi (0-25% of wheat flour) as an enzymatic improver with response surface methodology. Rregarding to the most important qualitative parameters of sponge cake such as moisture, density, porosity, color and textural profile, the best quantities of okara and kiwi in formulation were considered %29.7 and %12.45 respectively. According to the results, retrogradiation progress in optimized sample with okara and kiwi is significantly lower than control and cohesiveness of texture in 14 days shelf life is maintained. While in control sample, cohesiveness is reduced significantly in storage time. Furthermore, the springiness of its texture shows significant increase in storage time. Therefore, the use of optimal amounts of okara and also kiwiin in sponge cake formulations in addition of improving nutritional value, have considerable impact on reducing rate of retrogradiation process of products.

Sugar beet is considered as a one of the strategic industrial plant and the main source of sugar production in Iran and the world's. The present study was carried outduring the operation period timein 1392 on sugar beet sent to Hamedan sugar factory. The images of sugar beet samples was obtained using flat-bed scanner. Then the various characteristics of images, such as area of sugar beet, were determined using MATLAB software. The physicochemical analysis such as determining of sugar content, sodium, potassium and nitrogen was done. Result shows that some physicochemical properties are in related to the area of sugar beets. For instance, the correlation between area and sugar content, white sugar content, extraction sugar coefficient(ESC) and molasses was (R2=-0.696), (R2=-0.724) , (R2=-0.679) and (R2=0.459), respectively. According to these results, it can be concluded that the decrease in sugar content and increase the amount of impurities in sugar beet, was correlated with sugar beet area, and by increasing in the size and area of sugar beet, the sugar content was reduced and the impurities was increases.

Protein hydrolysate has been produced from White Cheek Shark meat (Carcharhinus dussumieri) by Alcalase with an activity of 35 Anson Unit/ Kg protein at 55oC. Hydrolysis carried out in four stages each at 10, 20 and 30 minutes. Functional properties such as oil absorption, foaming and emulsion properties, bulk density and viscosity of thehydrolysates examined at three different DHs of 1.91, 2.25 and 2.53%. There were nocorrelation between oil absorption capacity and foaming capacity with DH. Highest values for those properties observed at 2.25% DH (P>0.05). Foam stability decreased during storage at room temperature and the foam expansion totally destroyed after 60 min. Emulsificationcapacity decreased with increasing in DH. Emulsion stability was decreased with increasing in DH and time of storage (P>0.05). Bulk density increased with increasing in DH but the viscosity decreased. However, White Cheek Shark protein hydrolysates showed good functional properties.

Saffron which has traditionally been used in different industries as well as in folk medicine, is considered one of the valuable resources of antioxidant. However, there is little information about extraction of antioxidant compound from different parts of this plant especially its petal. Solvent-assisted extraction is considered one of the most important methods for extraction of the most valuable compounds from plant sources and is applicable in both laboratory and industrial scales. In this study, box-behnken design was used in order to investigate the effect of time (60-200 min), temperature (25-85oC) and ethanol percentage (20-60%) on the yield of polyphenol, flavonoid and anthocyanin, and also the antioxidant activity and optimization of extraction process. Results showed that maximum yield of antioxidant compounds is achieved with extraction time of 104.29 min, extraction temperature of 66.31oC and ethanol percentage of 58.96%. Under these conditions, the values were 1134 (mg gallic acid/100 g) for polyphenol, 85.44 (mg quercetin/100 g) for flavonoid, 3584.13 (mg/100 g) for anthocyanin, 60.60% for DPPH free radical scavenging activity and 3.24 (mM) for ferric ion reducing antioxidant power.

One of the common esterification methods to develop functional properties such as emulsification, is to use octenyl succinic anhydride (OSA). Therefore, in this research, some of the functional properties of OSA modified Persian gum (whole, soluble and insoluble fractions) in the optimal conditions with high degree of substitution were investigated. The FT-IR spectroscopy confirmed the formation of carbonyl groups in OSA treated gums (PG and soluble fraction). In addition, our findings on emulsifying properties demonstrated that modification of PG and its soluble fraction by using OSA improved their emulsifying properties 6 and 4 times in comparison to their untreated counterparts, respectively. Moreover, the microstructure of emulsions contained high number of small particles and longer physical stability. Furthermore, rheological investigations showed that flow behavior as well as apparent viscosities were reasonably different than untreated PG and its soluble fraction.

Mannoprotein/Mannan is a glycoprotein consists of a poly mannose backbone covalently attached to a protein moiety. It was extracted and purified from the cell wall of Kluyveromyces marxianus yeast. As for preparing a stable food emulsion, understanding the interaction between the components and their impact on the quality of the emulsion is very important. Therefore, in this study the effect of environmental stresses on some quality attributes of emulsions prepared with mannoprotein (20% w/w of the oil phase) at different conditions with varying pH (3 to 9), sodium chloride (0 to 500 mM) and temperature (30 to 90oC for 20 min) was investigated. Characteristics such as emulsion droplet diameter, zeta potential, viscosity and flow behavior in comparison with whey protein concentrate was measured. The results indicated that increasing droplet size, viscosity and flow behavior emulsion mannoprotein changes in pH 5 to 9, 500 mM salt concentration and temperatures 30 to 90oC was not significant (P<0.05). Results also showed despite the significant changes in surface charge droplets, stability of mannoprotein emulsions against environmental stress is due to the significant effect steric repulsion of poly mannose chains in addition to the electrostatic repulsion.

Given the importance of drying process in the rice production and in order to obtain the optimum time to achieve moisture balance in the tempering, influence of different drying temperatures (40, 50, 60 and 70oC) and drying time have been studied for four different paddy cultivars (Nemat, Neda, Pagouhesh and Pardis) in the time range of 0.5 to 8 hours at 10 levels of 0.5, 1, 1.5, 2, 3, 4, 5, 6, 7 and 8 hr (as independent variables) in a factorial experimental design based on randomized complete block with three replications. The results obtained in this study indicated that the gradient of the effective diffusion coefficient (K1, as dependent variable) in the early stages of tempering period (after completion of the heating up to one hour of rest) was much more than that of the later tempering stage (from one hour to two-hour relaxation time). The effective diffusion coefficient for the Nemat and Nedacultivers with a similar genotype was larger than that of Pagouhesh and Pardiscultivers. Based on the results obtained in this research, 1-hour relaxation time is recommended at drying temperatures less than 50oC and 2 hours for drying temperatures higher than 50oC. Adsorption and desorption of surface moisture in the relaxation period has a direct influence on grain fracture.

In this study, effects of different extraction methods, namely microwave-assisted hydrodistillation (MAHD) and solvent-free microwave extraction (SFME) were investigated in comparison with that of conventional hydrodistillation (HD) in terms of yield, active components, and antimicrobial activities (4 Gram-positive bacteria and 4 Gram-negative bacteria) of lemon verbena leaves essential oils (EOs). Gas chromatography/ mass spectrometry results indicated that geranial (25.54-28.53%), neral (20.76-23.51%), and limonene (11.21-12.51%) were main active components of lemon verbena EOs. There were significant differences among active components of EO obtained by SFME method with those of HD and MAHD methods (P<0.05). Antimicrobial activity of lemon verbena EO obtained by SFME method was higher than those of HD and MAHD methods, which is due to its higher oxygenated components such as geranial (increased by 4.96-11.70%) and neral (increased by 4.09-13.24%). Hence, SFME method can be proposed as a fast, efficient, and selective alternative method for extraction of EO from medicinal plants.