Journal of Food Biosciences and Technology
Volume:2 Issue: 1, Winter-Spring 2012

Mastitis is an inflammatory reaction of the mammary tissue in response to the introduction and multiplication of pathogens and is characterized by increasing somatic cell count (SCC) in milk. The main objective of present study is to assess the probable associations between somatic cell (SC) levels and calcium and phosphorus and ratio of Ca/P in raw milk. Milk samples were collected from individual quarters of 30 Holstein cows and divided into three groups based on SC level, including: low SC level (800,000 cells ml-1), followed by calcium and phosphorus analysis. Significant negative association between SC level and Ca, P, Ca/P ratio and titratable acidity (TA) of raw milk were found, while pH increased significantly by increasing SC level. It might be concluded that nutritional quality of milk and milk products strongly depends on the establishment of effective control measures for SC levels in raw milk.

Oxidation might be regarded as one of the most important reaction in oils and fats. Prooxidants namely iron and copper intensify and catalyze the oxidation while the chelating agents might retard or delay this process. Citric acid, phosphoric acid, some of phenolic compounds and phospholipids are considered as the compounds that chelate the prooxidant metals and through this mechanism stabilize the oil. Coffee extract, due to the nonenzymatic browning reactions during roasting of coffee and the resultant products might play an important role in the chelation of metals. The object of this research work is to study the chelation power of the coffee extracts on the stability of oils and fats. Two types of coffee; Arabica and Robousta, both green and roasted were selected for this study. Isopropanol was employed as a solvent to obtain the extract. Peroxide value determinations and induction period measurements using Rancimat apparatus, measuring the secondary oxidation products were employed as means to evaluate the chelating power of coffee extracts at 0.15% concentration and compared to citric acid a well known chelating agent at 0.01% concentration. It was concluded that both roasted and green coffee extracts due to the presence of phenolic compounds in the green beans exhibited antioxidant activity but the extracts were deficient in chelation of metals particularly copper.

Yoghurt is a popular healthy food, consumed by many people. The popularity of this product made it possible to use it as a base in order to produce probiotic preparations. Prebiotics are used for better growth and survival of probiotic bacteria as well as to improve organoleptic, rheological and technological properties of probiotic yoghurt. The aim of this research was to study physicochemical changes and survival of probiotic bacteria in synbiotic yoghurt. In this study, prebiotics including Lactulose, Inulin and Oligofructose were used separately and probiotic bacterium Lactobacillus casei was used to prepare the yoghurt. Samples were stored at 4°C for 21 days and during this time pH, acidity, syneresis and probiotic counts were investigated and compared to the control (probiotic yoghurt without prebiotics). The results showed that the highest pH, the most probiotic counts and the highest taste and texture scores were related to the sample which had Inulin. In contrast the control sample had the least probiotic count and the lowest score concerned with taste and texture. This sample had the least percent of syneresis which wasnt significantly different from others. The most and the least acidity were related to the control sample and the yoghurt containing Lactulose, respectively. The results suggested positive effect of synbiotic in probiotic yoghurt. Based on this study, since prebiotics improve physicochemical properties and enhance probiotic bacteria survival they can be incorporated in yoghurt formulation.  The results show that Inulin has a better effect on physicochemical changes and probiotic bacteria survival as compared to other prebiotics.

Olives belong to the family of olea europaea L. is a popular fruit tree. The fruit and the oil extracted from it is consumed worldwide particularly in the Mediterranean regions. In this study changes in the fatty acid composition of the oil extracted from olive fruit during the course of maturation is investigated. This work is concerned with the best harvesting point when oleic acid the predominant fatty acid reaches its maximum concentration. Three different varieties of olives from Fars province were chosen and subjected to oil extraction. The quantitative and qualitative determinations concerned with the fatty acids were carried out on the oil and concluded that maturation of olives depending on the variety played an important role in the fatty acid composition of the extracted oils.

Mayonnaise is probably one of the most widely used sauces worldwide. The oil content of traditionally mayonnaise is more than 65%. Fat has a role in creating viscosity, color and texture but might cause many diseases and disorders in human. In this study the influence of modified wheat bran as a fat replacer on the rheological properties of low fat mayonnaise was studied and compared to a blank sample containing starch. Low fat mayonnaise samples containing different amount of modified wheat bran (1, 2 and 3%) and blank were produced. The rheological analysis comprising the evaluation of flow properties and oscillatory tests were carried out by Rheometer. The results of flow curves showed that all the mayonnaise samples exhibited nonnewtonian, pseudoplastic behavior which fitted by Herschel-bulkley model and the factors related to this model were specified in the samples and blank. Storage and loss modulus obtained by the frequency sweep measurement classified mayonnaise samples into weak gels. The results showed that flow properties of mayonnaise samples depended on shear rate. The results indicated that separation between two phases of emulsion didn’t occurred and all the samples were stable. The sample containing 1% modified wheat bran was behaving most similar to the blank and due to the best appropriate ratio between cellulose and starch was selected as the superior sample.

Iran is considered number one producer of pomegranate throughout the world. The oil extracted from pomegranate seed is considered to have great medical and nutritional values, therefore the study is concerned with this unique and valuable oil specially its chemical attributes. Five different varieties of pomegranate were obtained from Saveh Pomegranate Research Institute. The seeds were separated, dried and subjected to Soxhlet apparatus to extract the oil. Fatty acid profile, Iodine value, non saponifiable matters, sterols, tocopherols, phosphorus and phospholipids were determined both qualitatively and quantitatively in the extracted oil. The results of this research indicated that the predominant fatty acid (higher than 70%) was punicic acid.  Beta-sitosterol and γ-tochopherol were the predominant sterol and tochopherol present in the extracted oil respectively. The results of this study showed that there are significant differences concerned with the elements under investigation in this research among the varieties tested.

The combination of pulsed vacuum osmotic dehydration and microwave drying of garlic bulbs were examined. The response surface methodology (RSM) was used to determine the effect of NaCl concentration (8%-20%), osmotic solution temperature (25-65°C), operation pressure (240-830 mbar), immersion time (20-300 min) and microwave power level (100-600 W) on water loss (WL), solids gain (SG), weight reduction (WR), hardness and shrinkage of samples. Analysis of the results showed that by increasing the osmotic solution concentration, temperature and immersion time, WL and WR will increase. The effect on SG was almost the same as WL except the effect of temperature. Increasing temperature resulted in an initial increase in SG for a period of time, followed by a decrease. NaCl concentration, temperature and immersion time showed the significant influence on hardness.

Acrylamide is a chemical compound that has been widely used since the last century for various applications. It is also formed from carbohydrate and amino acid containing foods by application of heat particularly in fried potato products, coffee and bread. Since bread is one of the primary foods of Iranian people, the determination of acrylamide content in bread might be considered important. This study is concerned with the qualitative and quantitative determinations of acrylamide in selected breads commonly consumed in Iran. The extraction level of acrylamide through three types of fibers, PEG, PDMS/DVB and PA, by DI-SPME-GC-FID in four selected types of baked breads were examined. The results of this study indicated that PEG fiber, as compared to the other fibers, was more reproducible and accurate. The concentration of acrylamide in Taftoon, Sangak, lavash and Barbari breads were, 146, 86, 26 and 135 (ppb) respectively.

Acidophilus milk after preparation, with the defined characteristics of pH, titratable acidity and viable counts of Lb. acidophilus, was kept at the refrigerator (5 °C) and changes of above mentioned parameters were evaluated during 21 days at 7-day intervals. The obtained results showed that the titratable acidity of product significantly (p≤0.05) increased over storage period, demonstrating the post acidification ability of Lb. acidophilus at low temperatures. The pH values of Acidophilus milk, due to the buffering capacity of milk, didn’t show significant (p≤0.05) decrease after 14 days, which this was contrary to the obtained result at 21 days of storage period. The viability of Lb. acidophilus significantly (p≤0.05) fell down in the first two assessments due to cold shock and increase of acidity and then raised at the last assessment due to the proteolytic activity of Lb. acidophilus, causing the liberation of nutritive amino acids.

The object of this study is to extract the oil from millets and evaluate the chemical properties of the extracted oil. Commercial millet oil was obtained by cold solvent extraction adopting soxhlet procedure. Quantitative and qualitative tests concerned with the non-saponifiable matter, fatty acid composition, phosphorus content representing total phospholipids, refractive index, peroxide, saponification, acid and iodine values were carried out on the extracted oil. The extracted non-saponifiable matter was fractionated into a number of chemical classes of compounds on TLC plates. The major two fractions; sterols and tocopherols were separated and extracted with ether. Gama tocopherol and β-sitosterol were the predominant tocopherol and sterol present in the millet oil. Prepared fatty acid methyl esters of the oil sample showed that linoleic (64.8 %), followed by oleic (24.2 %) and palmitic (6.1%) acids were the predominant fatty acids, in respective decreasing order. The oil contains considerable quantities of tocopherols which act both as vitamin E and antioxidant. The oil content of the seed depending on the types of extraction is low (4-7%) but due to its nature, being high in both linoleic acid and tocopherol, the purified oil might be employed as an ingredients in food formulation.