JOURNAL OF FOOD BIOSCIENCES AND TECHNOLOGY
Year:2016 | Volume:6 | Issue:1|Papers Count:10

This study investigates the oil extraction from Pistacia Khinjuk by the application of enzyme. Artificial Neural Network (ANN) and Adaptive Neuro Fuzzy Inference System (ANFIS) were applied for modeling and prediction of oil extraction yield. 16 data points were collected and the ANN was trained with one hidden layer using various numbers of neurons. A two-layered ANN provides the best results, using application of ten neurons in the hidden layer. Moreover, process optimization were carried out by using both methods to predict the best operating conditions which resulted in the maximum extraction yield of the Pistacia Khinjuk. The maximum extraction yield of Pistacia Khinjuk was estimated by ANN method to be 56.52% under the operational conditions of temperature and enzyme concentration of 0.27, pH of 6, and the Ultrasonic time of 4.23 h, while the optimum oil extraction yield by ANFIS method was 55.8% by applying the operational circumstances of enzyme concentration of 0.30, pH of 6.5, and the Ultrasonic time of 4.55 h. In addition, mean-squared-error (MSE) and relative error methods were utilized to compare the predicted values of the oil extraction yield obtained for both models with the experimental data. The results of the comparisons revealed the superiority of ANN model as compared to ANFIS model.

This paper reports on the use of Artificial Neural Networks (ANN) and Partial Least Square regression (PLS) combined with NIR spectroscopy (900-1700 nm) to design calibration models for the determination of sugar content in sugar beet. In this study a total of 80 samples were used as the calibration set, whereas 40 samples were used for prediction. Three pre-processing methods, including Multiplicative Scatter Correction (MSC), first and second derivatives were applied to improve the predictive ability of the models. Models were developed using partial least squares and artificial neural networks as linear and nonlinear models, respectively. The correlation coefficient (R), sugar mean square error of prediction (RMSEP) and SDR were the factors used for comparing these models. The results showed that NIR can be utilized as a rapid method to determine soluble solid content (SSC), sugar content (SC) and the model developed by ANN gives better correlation between predictions and measured values than PLS.

Tea might be considered as the most popular drink in Iran as well as some other parts of the world. Its popularity to some extent depends on its flavor and some other constituents present in its leaves or extract. Black tea samples from various agro climatic zones of northeast of Iran were evaluated for the chemical constituents, polyphenols and metal analysis that determine the quality perception. Black tea epicatechins, namely epigallocatechin gallate (EGCG), epicatechin gallate (ECG), epigallocatechin (EGC) and epicatechin (EC) were also assessed by HPLC. Furthermore, for metal analysis, the level of Mn, Cu, Pb and Ni elements were evaluated in black tea from the five tea growing districts of north Iran. The results confirmed that the total polyphenol concentration in black tea varied from 17.10 g/100g to 12.20 g/100g, whereas the catechins content ranged from 17.20 mg/g to 15.80 mg/g. Furthermore, significant differences were detected in the chemicals content between different black tea samples. In general, the contents of caffeine and water extract in Lahijan sample were found to be the highest. The Mn content was found in the range of 702 and 731 mg/kg and copper ranged between 24.30 and 32.60 mg/kg. The Lead content in the samples were in the range of 0.22 and 0.35 mg/ kg. Nickel concentration in black tea leaves ranged between 2.31 and 3.67 mg/ kg. The results of the evaluation of tea confirmed that the level of elemental contents in all of the tea sample were completely lower than the acceptable limit according to the international standards. It was noted that in different black tea samples, Lahijan produced the best quality tea followed by Tonekabone.

The essential oil of Verbena officinalis growing in Iran was extracted using hydro-distillation method and the antibacterial and antioxidant activities were evaluated. The antibacterial activity of the essential oil against a Gram-positive (S. aureus ATCC25923) and Gram negative (E. coli ATCC 25922) were examined. The results obtained revealed that the essential oil exhibited variable levels of antibacterial activities against tested bacterial strains and highest sensitivity to essential oil of V. officinalis was observed by E. coli ATCC 25922. The antioxidant and free radical scavenging activity of the obtained oil was tested by means of 1, 1-diphenyl-2-picrylhydrazyl radical (DPPH) assay and b-carotene bleaching test. In the DPPH assay, while the free radical scavenging activity of the HD oil showed inhibitions of 51.4, 55.00 and 66.30% at 0.25, 0.5 and 1.00 mg/ml, respectively, in the b - carotene bleaching assay, the percentage inhibition increased with increasing the concentration of the oil. The results have shown that the essential oil of Verbena officinalis possess antioxidant and antibacterial activities, and therefore it could be used as a natural preservative ingredient in food and/or pharmaceutical industries.

Chocolate milk is a popular tasteful dairy product and sugar is one of the main participants in its formulation. Massecuit III is a type of brown sugar consisting of phenolic compounds and other components that might exhibit antioxidant activity and could improve and affect the nutritional properties of the food. The aim of the present study is to replace some or all of the white sugar used in the formulation of pasteurized chocolate milk with massecuit III and evaluate its possible antioxidant activity. The new formulated product might be produced less expensive with improved quality. In order to evaluate the investigation, series of testes consisting of pH measurement, invert sugar content, sulfated ash, color determination and degree of the polarization were carried out on the sample (massecuit III). Phenolic compounds were determined by HPLC application and the antioxidant activity was evaluated using DPPH method. Total phenolic compounds in massecuit III was determined to be 126.27 mg/kg. It was concluded that by increasing the massecuit III concentration, the antioxidant activity was increased while other factors namely pH, acidity and bacterial counts were in the acceptable standard range.

The object of this research was to find an alternative to fungicide for the prevention of post-harvest fruits. Therefore the effect of Zataria multiflora essential oil on the quality of Sultana grapes following the harvest was investigated. The essential oil was extracted by hydro-distillation and analyzed using a combination of GC and GC/MS. The results indicated a high percentage of anti-fungal components such as Thymol (44.4%) and Carvacrol (26.3%) in the extracted essential oil. The grapes were contaminated with Botrytis cinerea spores suspension at the concentration of 5´105 per ml sterile distilled water. The samples were treated with suspension of 0 to 200 and 400 mgL-1 Zataria multiflora essential oil and stored at 4oC. Samples were examined and experimental design in a completely randomized design with three replications were employed. The results revealed that by increasing the concentrations of the essential oil, the anti-fungal activity against Botrytis cinerea was increased.

Date syrup powder is a new product which can be used as sugar substitute. First, the date syrup was spread out on a foil and placed in the oven at 60oC for 24 hours. Date syrup was separated from the foil and grinded. 2% agar and 2% starch were added and syrup with agar and starch that was in a lumpy shape were crushed and spread on the foil and placed at 60°C for 24 hours. Powdered granules, agar and starch were grinded for the second time, and spread out on the foil and placed at 60oC for 4 hours. Finally, granules were milled once more, and the color, moisture, sugar content, solubility and turbidity of the powder solution were measured. Statistical results were assessed by the use of SPSS19 Software and Paired samples test. Color strength, moisture and turbidity of purified powder solution with gelatin and Bentonite were evaluated. Solubility and fructose content were higher for the purified powder using alkaline method. Purified syrup using alkaline method is superior due to the fact that amino acids, pectin and colloids compounds are eliminated. As the result the color of the powder was more clear, moisture and turbidity were lower with higher solubility.

In this study the effects of autoclave, microwave and ultrasonic pretreatments with or without acid addition were investigated on the amount of glucose, soluble and insoluble lignin, furfural, yeast viability and bioethanol. The findings showed that autoclave-acid impregnated sample, has the highest glucose release from lignocellulose materials (14.61 and 14.95 g/l for solvent exposed and untreated sample, respectively) whereas for the control sample glucose content was at its minimal level. Pretreatments caused decrease in soluble and insoluble lignin and the highest decrease was caused by autoclave followed by microwave and ultrasonic pretreatments (p≤0.05). Moderate increase on furfural was observed for pretreated samples than the control. The most yeast viability and bioethanol content belonged to the autoclave samples especially the acid-impregnated ones (40.33%). Comparison between solvent treated and untreated samples indicated that significant differences were observed between the two tested groups (p≤0.01) in terms of lignin, cell viability and ethanol content but glucose and furfural didn’t show a significant difference.

The species of Lactobacillus are widely present in many natural environments that are important in fermented processes. Among these species some belong to the lactic acid bacteria group that are useful in fermented food. One of the species of lactobacilli group such as L. plantarum provides health benefits, but their identification is one of the main issue. In order to proceed with this project, conventional culture method and PCR primers have been employed to identify L. plantarum. According to the conventional culture method, colonies were Gram-positive and catalase-negative in the form of coccoid-rod, short, long, thin and fine. Under the PCR conditions, L. plantarum and L. brevis strains were detected in only one sample at 25oC. In chemical technique, L. plantarum was separated from L. brevis in four cultures medium with 4-7% NaCl where L. brevis became inactive. The isolated L. plantarum that was used in the fermented cucumbers prevented the growth and development of pathogenic organisms.

Olive oil in general due to it monounsaturation, stability, nutritive value, consistency, taste and aroma might be considered as a valuable and luxury oil. Annual importation of olive oil to Iran from Mediterranean countries is on a large scale although some olive oils are produced in Iran particularly in the north and some plantation has been applied in different provinces particularly in Fars. The value of this luxury oil either imported or produced internally provides a ground for adulteration. The aim of this work is to evaluate the chemical characteristics of three varieties (Mari, Arbequina, Koroneiki) of olive oils from two regions (Fadak and Gilvan).Three varieties of olive fruit in two regions were selected and the extracted oils were subjected to a series of chemical tests consisting of acid value, peroxide value, Iodine value, fatty acid profile as well as phenolic content and sterol composition. The results indicated that all of the samples in terms of acid and peroxide values were consistent with the values defined for extra virgin olive oil. The fatty acid composition indicated that oleic acid was the predominant fatty acid ranging from 56 to 77% of the total fatty acids indicating the Italian and Spanish origins. The analysis of sterol fraction showed that b-sitosterol was the major and the predominant sterol (88%). The phenolic concentration in this study was 100-250 mg/kg as gallic acid. The study illustrated that the investigated samples were in agreement with the standard of CODEX and the Iranian national standard in spite of differences obtained.