Journal of Food Biosciences and Technology
Volume:6 Issue: 2, Summer-Autumn 2016

Mustard is a natural multi-functional additive with strong hot flavor. In this research, powdered yellow mustard (Sinapis alba) was heated by 21 different thermal processes, statistically designed by Response Surface Methodology to evaluate the effects of combinations of heating media (hot air, hot water and steam) and heating time (0-20 min) on residual myrosinase activity, the minimum inhibitory concentration (MIC), color characteristic and also the major phenolic constituents of each treated sample. The optimum process, for the desirable function was 5 min of heating by hot air. Under optimal conditions, myrosinase activity was reduced by 44%, MIC and lightness (L*) were approximately unchanged, redness (a*) and yellowness (b*) were increased as compared to the control. In spite of the fact that the  total phenolic content were reduced severely (>90%) due to deheating processes, but the chromatography spectrum indicated that some compound (caffeic acid) were newly formed or existed in higher concentration (Sinapine) particularary in steam treated samples.

This study was aimed at probiotication of tomato and carrot juices using Lactobacillus plantarum, Lb. fermentum, Lb. casei, Lysinibacillus sphaericus and Saccharomyces boulardii. To enhance the stability, the probiotic cultures were micro-encapsulated using alginate coated chitosan beads. Tomato and carrot juice samples were pasteurized for 20 min at 63 °C. Lb. fermentum, Lb. plantaram, Lb. casei and Lysinibacillus sphaericus, Saccharomyces boulardii were inoculated and incubated at 37 °C for a period of 72 h. After the probiotication the pH decreased from6.8to 4.5 and correspondingly increased the titratable acidity from 0.12 to 0.36% during the period. Among the probiotic strains the viable cell count were increased from 6.5 to 8.9 log CFU/mL in Lysinibacillus sphaericus and5.2 to 7.6 log CFU/mLin Saccharomyces boulardii, during 24 to42 h and later it decreased slowly.Viability of encapsulated cells were higher than free cells in tomato and carrot juices stored at 4 °C over a period of 5 - 6 weeks indicating better cell protection in the former. However, the addition of probiotic beads influenced the sensory quality of the product by increasing the swallowing difficulty and remaining particles of the encapsulated ones increased the turbidity of vegetable juices.

In this study the reliability of using response surface-neural network method to predict the osmotic dehydration properties of crookneck squash has been investigated. In order to carry out this project, the osmotic solution concentration, the osmotic solution temperature and immersion time were chosen as inputs and solid gain and water loss were selected as outputs of the designed network. The results showed that the optimal points for the artificial neural network parameters such as the number of neurons, momentum coefficient, learning epoch and the rate to predict water loss and solid gain were 15.75, 0.90, 4999.98 and 0.55, respectively. The results also demonstrated that the model was able to forecast water loss and solid gain with R2 values equal to 0.967 and 0.890 where relative error values corresponding to each of these factors were estimated at 0.0205 and 0.0872, respectively

Fermented cucumber is a traditional lactic acid fermentation that is related to the presence of microorganisms. In this study, the use of suitable L. plantarum starter culture with L.bulgaricus and S. thermophilus to improve the cucumber fermentation process with high quality has been studied. Cucumbers in brine containing 4 to 6% NaCl and 0.2 to 0.4% Inulin (w/v) were inoculated with different LAB strains and analysed for microbial and physicochemical characteristics. The numbers of LAB strains were 7.46 log10 cfu/ml in a solution containing 4% NaCl, 0.4% Inulin and a mixed starter culture on the sixth day. The initial salt concentration of 4% (w/v) and Inulin concentration of 0.4% was favored for the rapid growth of LAB. In the mixed starter culture, the value of titratable acidity and pH were 0.6% and 3, respectively, on the sixth day. The inoculated 6% NaCl and 0.4% Inulin solution with mixed starter culture had lower numbers of aerobic mesophilic and yeast (6.38 and 6.65 log10 cfu/ml) on the sixth day. The inoculated 4% NaCl solution had lower hardness and l*, a*, b* values and the highest ranking in flavor. In order to control the fermentation of cucumbers, it is advisable to make heavy inoculation with the mentioned strainsthat produce high quality uniform and safe products.

In this research, the functionality of sweet Basil seed powder (Ocimum basilicum L.) on Buguette bread quality and its potential application in retarding the staling process has been studied. Three different concentrations of the powder (0.5%, 1% and 1.5%, w/w, flour basis) were applied. The effects of powder on the rheological properties of dough were also investigated instrumentally by using farinograph and extinsograph. Sweet basil seed powder effects on the physical properties of bread were established by measuring the texture, the loaf volume and the crust colour of baguette bread with a texture analyser and Hunter Lab instrument respectively. All of the instrumental evaluations and sensory tests were applied on the bread after the 1st, 3rd and the 5th days of production. The results indicated that with the addition of 0.5% sweet basil seed powder to the formulation, the staling and sensory characteristics were improved.

Degumming and neutralization processes are two essential stages carried out on crude edible oils in order to remove some unwanted impurities namely gums and free fatty acids. In this research study two popular less expensive commercial oils that are consumed to a great extent namely soyabean and sunflower seed oils are selected and subjected to both degumming and neutralization processes as recommended and described by the conventional methods. The effects of these two processes are investigated on both oils qualitatively and quantitatively. Minor changes were detected in fatty acid composition meaning that slight oxidation reactions have taken place during the operations. The acid values representing the fatty acid concentrations were reduced as the result of neutralization with the lye solution. The peroxide value that indicates the primary oxidation products has been increased due to the oxidation chain reactions producing hydroperoxide. The phosphorus, Iron and copper concentrations as well as the induction periods were reduced. The reduction in the induction period might be the result of phospholipid removals since they act as synergist with the tocopherols. The nonsaponifiable matter representing sterols, 4 methyl sterols, triterpene alcohols, tocopherols, hydrocarbons and some other components were reduced at the end of neutralization process along with the soap removal.

Regular consumption of seafood has been widely recommended by the authorities. However, some species especially benthic crustaceans accumulate heavy metals. In addition, the health risks associated to the consumption of such seafood might increase if the consumers use cooking methods that enhance the concentration of heavy metals. In this study, the effects of different cooking methods (boiling, steaming and frying) on the concentrations of lead (Pb) and cadmium (Cd) in shrimp and lobster were studied. Samples were prepared by wet digestion and the contents of heavy metals were measured by graphite furnace atomic absorption spectrophotometer. Mean concentrations of lead and cadmium for raw samples of shrimp and lobster were 75.67±15.31 and 26.00±8.00 µg/kg and 316.67±66.58 and 195.33±131.46 µg/kg respectively. The findings indicated that the highest contents of lead and cadmium were observed in the fried samples (p<0.05), however the differences were not significant for cadmium. According to the results, boiling and steaming are suggested as the best cooking method to provide healthful seafood.

This paper presents the results of studies concerned with the preparation of fresh food foams based on egg white and various hydrocolloids including Iranian gum tragacanth, guar and xanthan gums at different concentrations (0.002-0.040% w/w). The basic physical parameters of the obtained foams such as overrun, stability and morphology of gas bubbles were measured. Viscosity measurements were also performed, and Power law model was applied to describe the flow behavior of gum solutions. The addition of hydrocolloids into the egg white solution had a deteriorative effect on the foam expansion but enhanced the foam stability. In addition, ANOVA showed that by increasing the concentration of the hydrocolloids in egg white solution significantly decreased the overrun and foam drainage (p<0.05). The stability of egg white foam in the presence of gum tragacanth was lower than xanthan gum and higher than guar counterpart. However, higher overrun was observed for tragacanth when compared to xanthan. Optical microscopy also showed smaller bubbles for foams which stabilized with tragacanth or xanthan in comparison with larger ones in the case of guar gum that stabilized the egg white foam. Rheological measurements also showed a pseudoplastic behavior for gum solutions at higher concentrations.

Due to the importance of essential oils and their use in various industries, the essential oils of four types of citrus consisting of orange (C. sinesis), tangerine (C. reticulate), sweet lemon (C. limetta) and sour lemon (C. limon) were extracted and subjected to chemical analysis to identify and evaluate the chemical constituents of the oils. The average essential oils of orange, tangerine, sweet lemon and sour lemon peels were 1.48%, 0.90%, 0/54% and 0.46% (w/w) respectively. Seven compounds were identified in the orange peel essential oil where limonene (64.87%) followed by N-methyl-D3-aziridine (10.78%), cytidine (8.55%) and propane, 1,1, - oxybis (4.99) were the major components. Seventeen compounds were identified in tangerine peel essential oil where the main components were limonene (28.10%), xanthotoxin (18.40%), cytidine (8.34%) and 1,4-diethynylcyclobutene (4.73%). Eighteen compounds were identified in the essential oil of sweet lemon peel where limonene (49.79%), xanthotoxin (12.62%), 6,6-dideutero-nonen-1-ol-3 (10.20%) and 4-vinyl- 2-methoxy-phenol (5.20%) were the major components. Seven compounds consisting of limonene (83.03%), cytidine (4.16%), N-methyl-D3-aziridine (4.42%), 4- vinyl-2-methoxy-phenol (2.79%) were the major constituents of sour lemon peel essential oil in respective decreasing order. Limonene was the predominant compound in all the citrus fruit peels and showed the highest concentration of this compound among the samples examined.

In this study, an analytical method is developed to determine 15 polycyclic aromatic hydrocarbons (PAHs) in olive and refined pomace olive oils using HPLC coupled with a fluorescence detector. The standardised method of ultrasound-assisted solvent extraction consisted of liquid–liquid extraction with organic solvent and purification on C18 and Florisil bonded-phase cartridges was modified for the refined olive and refined pomace olive oils. The modification included the clean-up by solid phase extraction on an amino cartridge eluting with toluene. The limits of detection and limits of quantitation were 0.19-0.97 µg kg-1 and 0.57-2.93 µg kg-1, respectively. The PAHs recoveries ranged from 75% to 110% (RSD = 3–8%).The performance of the present method was evaluated for determination of PAHs in various types of olive oils samples, and suitable results were obtained. The variable levels of PAHs were detected ranging from 0.61 to 6.30µgkg-1 in real samples.