Determination of nickel and chromium content in serum, emulsion, skin and viscera of Iranian tuna fish

1409-1414Contamination of heavy metals, namely, nickel and chromium was evaluated in serum, emulsion and tissues of Euthynnus affinis and Thunnus tonggol collected from Persian Gulf. The concentration of metals was determined by Graphite Furnace Atomic Absorption Spectrometry (GFAAS). Tissues analysis revealed that viscera in Euthynnus affinis accumulated the highest levels of Ni and Cr. Nickel concentration in the non-edible parts of the examined fish (viscera in both fish species and skin in Thunnus tonggol) were higher than the established values by World Health Organization (WHO), whilst concentration of chromium for all samples were higher than maximum permissible limits determined by the WHO, except for serum of Thunnus tonggol

Occurrence of Bacillus cereus in raw milk receiving from UF-Feta Cheese Plants

Background and Objective: Milk and milk products are very suitable medium for growing microorganisms (e.g. Bacillus cereus). B. cereus is spore former bacilli, which easily survives during pasteurization and makes several problems in dairy industries. The aim of this study was to investigate aerobic spore and B. cereus of receiving raw milk from three UF plants. Materials and Methods: Samples were gathered from raw milk transport tankers arrived to plants during 30 days in winter. Also, the swab test was used for detection of B.cereus residual on milk contact surfaces. Results: High contamination level of aerobic spores (AeSC) and especially B.cereus were found in most samples compared with the criteria established by national and international standards. Although total viable count (TVC) in samples from industrial farms (IF) was lower than those from traditional farms (TFs) and milk collection centers (MCCs), considerable AeSC and B.cereus were transmitted to the UF plants from IFs. The highest and lowest TVC and B.cereus were found in samples from IFs and MCCs, respectively. In addition, our investigation in IFs revealed that teats contamination to soil and feces, as well as contaminated bedding might were the most important sources of B. cereus and AeSC of raw milk. Moreover, the results of swab tests confirmed that the “cleaning in place” system may not remove B.cereus effectively. Conclusion: It seems that for classifying raw milk quality, AeSC might be used as a more effective quality factor than TVC. Management commitment is effective to improve quality by balance between the amount and quality of receiving raw milk. This leads to the lower contamination in dairy plants and final products

Determination of Antioxidative Effect of Achillea Millefolium Essential Oil on Mayonnaise Stability by Rancimat Method

Background and Aim: Diabetes is a major public health problem worldwide. Oxidative stress is a risk factor in diabetes. The aim of this study is to evaluate the possible beneficial effect of caffeic acid (CA) on serum lipid parameters and atherogenic index in alloxan-induced male diabetic rats. Materials and Methods: 40 male Wistar rats were randomly divided into 4 groups: group I as the healthy control group, group II as the healthy group treated with CA (50 mg/kg i.p. daily), group III as the diabetic control group and group IV as the diabetic group treated with CA (50 mg/kg i.p.daily). Diabetes was induced in the 3rd and 4th groups by the injection of alloxan monohydrate (100 mg/kg s.c). After seven weeks, animals were anaesthetized and blood samples were collected. Then, the serum level of fasting blood glucose (FBS), lipid parameters and the atherogenic index were measured. Results: The serum level of FBS, cholesterol, low density lipoprotein (LDL-C) and atherogenic index significantly decreased in the diabetic group treated with CA compared with the untreated diabetic group. The serum level of high density lipoprotein (HDL-C) significantly increased in the treated diabetic group compared with the untreated diabetic group. Conclusion: The results of this study indicated that CA has beneficial effects on serum blood glucose, lipid profile and atherogenic index in type 1 diabetic rats

SPME/GC-MS characterization of volatile compounds of Iranian traditional dried Kashk

The volatile aromatic components in cow’s or sheep’s milk Kashk samples collected from 11 regions of Iran were extracted by solid-phase micro-extraction and analyzed by GC/MS. Alkenes, aldehydes, free fatty acids, esters, terpenes, alcohols, sulfur compounds, and ketones were the most frequently used compounds in samples. Same volatile compounds were identified in sheep’s and cows’ milk Kashk, whereas the numbers of compounds were different. The results from principle component analysis (PCA), performed to distinguish flavor from different regions, showed that Kashk samples are divided into three groups, in which flavor of some regions in two groups is affected by ingredients

Antioxidant Capability of Ultra-high Temperature Milk and Ultra-high Temperature Soy Milk and their Fermented Products Determined by Four Distinct Spectrophotometric Methods

Background: Due to the recent emerging information on the antioxidant properties of soy products, substitution of soy milk for milk in the diet has been proposed by some nutritionists. We aimed to compare four distinct antioxidant measuring methods in the evaluation of antioxidant properties of industrial ultra-high temperature (UHT) milk, UHT soy milk, and their fermented products by Lactobacillus plantarum A7. Materials and Methods: Ascorbate auto-oxidation inhibition assay, 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) free radical scavenging method, hydrogen peroxide neutralization assay and reducing activity test were compared for the homogeneity and accuracy of the results. Results: The results obtained by the four tested methods did not completely match with each other. The results of the DPPH assay and the reducing activity were more coordinated than the other methods. By the use of these methods, the antioxidant capability of UHT soy milk was measured more than UHT milk (33.51 ± 6.00% and 945 ± 56 μM cysteine compared to 8.70 ± 3.20% and 795 ± 82 μM cysteine). The negative effect of fermentation on the antioxidant potential of UHT soy milk was revealed as ascorbate auto-oxidation inhibition assay, DPPH method and reducing activity tests ended to approximately 52%, 58%, and 80% reduction in antioxidant potential of UHT soy milk, respectively. Conclusions: The antioxidative properties of UHT soy milk could not be solely due to its phenolic components. Peptides and amino acids derived from thermal processing in soy milk probably have a main role in its antioxidant activity, which should be studied in the future

OXIDATIVE STABILITY OF MAYONNAISE SUPPLEMENTED WITH ESSENTIAL OIL OF ACHILLEA MILLEFOLIUM SSP MILLEFOLIUM DURING STORAGE

Lipid oxidation is the main chemical process affecting mayonnaise deterioration. Today, essential oils from aromatic plants have been qualified as natural antioxidants and proposed as potential substitutes of synthetic antioxidants in food products. In this research, antioxidant activity of Achillea millefolium essential oil was determined based on oxidative stability of treated mayonnaise (homogenized) during 6 months of storage at 4°C. The following analysis were performed: peroxide value (PV), anisidine value (AV), Totox value and thiobarbituric acid (TBA) to assess the extent of oil deterioration. Mayonnaise samples were divided into three experimental treatments, namely: E.O (essential oil in concentrations: 3.83, 5.85 and 7.2 mg/ml), T (TBHQ in concentration: 0.12 mg/ml) and C (control: no antioxidant). Subsequently, the samples from each treatment were stored at 4 oC. The results showed that the treatments containing essential oil and TBHQ significantly reduced the oxidation (p < 0.05), while the control sample was oxidized faster. Among the essential oils, concentrations of 5.85 and 7.2 mg/ml showed the best antioxidant activity. PV, TBA, AV and totox values increased during the storage time for all treatments. Our results suggest that essential oil of Achillea millefolium has potential source of natural antioxidant for the application in food industries to prevent lipid oxidation particularly lipid-containing foods such as mayonnaise, due to its reaction with oxidative free radicals and therefore can increase food shelf life

Zinc and Copper Concentrations in Human Milk and Infant Formulas

Objective: Available accurate data on the concentrations of copper (Cu) and zinc (Zn) in human milk throughout lactation and infant formulas is important both for formulating nutritional requirements for substances and to provide a base line for the understanding the physiology of their secretion. The objective of this study was to analyze the concentrations of zinc and copper in infant formulas and human milk during prolonged lactation. Levels of these metals were examined in relation to selected parameters such as age, weight, height, education and occupation of mothers. Methods: Thirty mothers referred to the selected clinics in Tehran entered the study. Human milk samples were collected at 2 months postpartum. Zinc and copper concentrations were determined by atomic absorption spectrophotometer. Findings: The mean values of Zn and Cu in human milk were 2.95±0.77mg/L and 0.36±0.11 mg/L. The mean values of Zn and Cu in infant formulas were 3.98±0.25 mg/L and 0.53±0.17mg/L. Conclusion: No significant relationship was found between levels of trace elements in human milk and evaluated parameters such as age, weight, height, education and occupation of mothers. The concentrations of zinc and copper in breast milk were lower than those reported in the literature