نشریه بهداشت مواد غذایی
سال دوازدهم شماره 2 (پیاپی 46، تابستان 1401)

Microplastics (MPs) have been identified as emerging environmental pollutants classified as primary or secondary based on their source. Composition, shape, size, and color, among other characteristics, are associated with their capacity to access the food chain and their risks. While the environmental impact of MPs has received much attention, the risks for humans derived from their dietary exposure have not been yet assessed. Several institutions and researchers support that the current knowledge does not supply solid data to complete a solid risk characterization of dietary MPs. The aim of this paper is to review the current knowledge about MPs in foods and to discuss the challenges and gaps for a risk analysis. The presence of MPs in food and beverages has been worldwide observed, but most authors considered the current data to be not only insufficient, but of questionable quality, mainly because of the outstanding lack of consensus about a standardized quantifying method and a unified nomenclature. Drinking water, crustaceans/molluscs, fish, and salt have been identified as relevant dietary sources of MPs for humans by most published studies. The hazard characterization presents several gaps concerning the knowledge of the toxicokinetic, toxicodynamic, and toxicity of MPs in humans that impede the estimation of food safety standards based on risk.

Brucellosis is one of the most important zoonotic bacterial diseases in humans and vertebrate animals. Lactic acid bacteria (LAB) and their production compounds have been proposed as potential biocontrol agents in biofilm formation. The present research aimed to determine the effects of cell-free supernatant (CFS) from Lactobacillus acidophilus on the biofilm production of Brucella isolates from raw sheep milk of Mahabad city (Iran). In this study, 100 sheep milk samples were randomly collected from different urban and rural areas of Mahabad. To isolate Brucella, the samples were cultured in Brucella broth and then streaked on Brucella agar with the selective supplement, and to identify the species of Brucella, related metabolic tests were performed. The biofilm production capability of the isolates, as well as the antibiofilm activity of the CFS, were evaluated by the microplate assay method. The results showed that out of 100 milk samples, 3 samples (3%) are contaminated with Brucella melitensis. Also, all three isolates were biofilm-formers. Two isolates were recognized as moderate and one isolate as a strong biofilm-former. Different concentrations of CFS reduced the biofilm production of isolates significantly (P˂ 0.01). Also, the concentration of 10% of CSF showed the highest antibiofilm activity. From the findings, it can be concluded that Brucella contamination in raw sheep milk in the Mahabad region is relatively high. There is a need for a full performance of Brucellosis screening and vaccination programs in livestock herds of the region. It can also be concluded that the CFS of L. acidophilus can remove Brucella biofilm. Therefore, L. acidophilus CFS as an antibiofilm compound can be proposed to control the growth of Brucella.

This review aims to evaluate the intrinsic properties and different applications of phycocyanin pigment in the food and pharmaceutical industries. In addition, in each section, a detailed history of the research conducted in the field of phycocyanin is presented. Phycocyanin is a blue pigment, a light receiver with antioxidant and fluorescent properties in cyanobacteria, and two algae from the genus rhodophytes and cryptophytes. Phycocyanin pigment consists of two relatively similar subunits α and β. The alpha chain contains one phycocyanobilin attached to cysteine 89 and the beta chain contains two phycocyanobilins attached to cysteines 84 and 155. Phycocyanin is commercially produced from spirulina algae (spirulina platensis), in the form of photoautotrophic cultures, and open environments in large ponds or pools in tropical or subtropical areas at the edges of oceans. This pigment can be extracted from the mentioned algae by using different techniques such as enzymatic method, ultrasound, freezing-defrosting, mineral solvent, homogenization, stress and osmotic shock, high hydrostatic pressure, ultracentrifuge, and ultra homogenization. Depending on the extraction conditions, each method has its advantages and disadvantages, but the enzymatic and ultrasound methods are more efficient than other methods. Phycocyanin has many medicinal and therapeutic properties, including anti-cancer and anti-inflammatory; In addition, the positive effect of this pigment on nerve cells, kidneys, and the immune system has been confirmed. Phycocyanin, having three colorings, antioxidant and antimicrobial properties, has the potential to be used in various food formulations, such as yogurt, cheese, ice cream, etc., which have been proven in various research.

This study aimed to evaluate the effects of additive garlic essence and astaxanthin in macrostructural and nanostructural forms in rainbow trouts’ feed on preservative and sensory properties of meat and biometric measures. Garlic essential oil was produced by Clevenger apparatus and nanostructural forms were prepared by emulsifier and by mixing organic and aqueous phases. Seven hundred fish were equally and randomly divided into seven groups in separate pools with a control group. Six treatments were considered as follows: macrostructural garlic essence (T1), macrostructural astaxanthin (T2), nanostructural garlic essence (T3), nanostructural astaxanthin (T4), garlic essence with astaxanthin in macrostructural (T5) and nanostructural (T6) forms in diet. After 40 days, meat samples were evaluated for antioxidant and sensory properties. Biometric measurements were performed during the farming. Results showed a notable reduction of peroxide and thiobarbituric acid values and positive effects on the smell, flavor, and color of the treated groups’ meat compared to the control group (p<0.05). The meat texture was adversely affected in T1 (p<0.05); However, other treatments showed no effects on meat texture (p>0.05). The mortality rate was lower in the treated groups and the lowest FCRs (Feed Conversion Ratio) were observed in T3 and T4 groups. In general, it was discovered that garlic essence and astaxanthin in the diets improved antioxidant and sensory properties of meat and the biometric properties of rainbow trouts.

Non-thermal methods are introduced to lessen the color degradation and loss of nutritional compounds in fruit juices caused by conventional thermal pasteurization. This research aimed to investigate the effect of cold atmospheric gas phase plasma on physicochemical properties, bioactive compounds, and microbial load of red orange juice. The results show a significant difference (p≤ 0.05) between the samples treated with cold plasma and thermally pasteurized ones, in terms of physicochemical characteristics (acidity, pH, Brix, and color), bioactive compounds (anthocyanin, total phenol, and vitamin C) and microbial load (yeast/mold population and aerobic bacteria). The microbial load in the samples treated with cold plasma was within the acceptable range approved by the Iranian National Standard. The highest values of bioactive compounds (anthocyanin 51.248 mg/l, total phenol 1988.2 mg/l, and vitamin C 398 mg/l) were observed in the cold plasma pasteurized sample (at 20 kV, for 10 min and atmospheric gas). These values were significantly (p≤ 0.05) higher than those of thermally-pasteurized samples. The results showed that by applying the cold plasma process for the pasteurization of red orange juice, along with obtaining a healthier product, more bioactive compounds are preserved.

Nowadays, due to the disadvantages of the conventional methods of removing heavy metals, application of agricultural waste and by-products from food processing as a biosorbent has been considered. This study investigates the effect of orange peel concentration and agitation time on the quality characteristics and the level of heavy metals (Pb, Fe, Cu, Cd and As) in cold-pressed sesame oil. Results showed that the concentration of orange peel and agitation time significantly affected the quality characteristics and the level of heavy metals (p< 0.05). Compared to the control sample, the values ​​of conjugated diene, conjugated triene, peroxide value, free fatty acids and chlorophyll of samples containing 6 g/l of orange peel decreased by 68.10, 50.66, 49.61, and 15.1, 44 and 65.76%, respectively. But carotenoid and total polyphenol contents increased by 8.03% and 37.30%, respectively. Also, conjugated diene, conjugated triene, peroxide value, free fatty acids and carotenoid decreased up to 30 minutes, chlorophyll decreased up to 45 minutes, and total polyphenol increased up to 45 minutes of agitation. Comparing with control sample, the content of lead, iron, copper, arsenic and cadmium in the oil sample containing 6 g/liter orange peel, decreased by 24.31, 43.49, 47.16, 36.49 and 21.53% respectively. Increasing agitation time up to 60 minutes, decreased the level of Pb, Fe, Cu, As and Cd by 35.87, 50.65, 56.12, 47.81 and 21.50%, respectively. The results showed that orange peel as a biosorbent can improve quality, reduce heavy metals in oil and create added value.