فصلنامه پژوهش های صنایع غذایی
سال بیست و هفتم شماره 2 (تابستان 1396)

Fish is a source of valuable protein that due to the high variety of species, has a good ability to meet some of the human protein is required, but the quality of fishery products are rapidly degrading. In this study, the effect of gutting and filleting of common carp (Cyprinus carpio) on some microbiological (total bacterial load and psychrophilic), sensory (taste, odor, texture, color, and overall acceptance) and physicochemical indices including pH, wet, expressible water, thiobarbituric acid, total volatile nitrogen and free fatty acids during the 12 days of refrigerated storage (5̊C) were investigateded. In per treatment 3 replicates were prepared and sampling was carried out at 0 and days 1, 2, 3, 6, 9 and 12 to determine changes of mentioned parameters. The physicochemical and microbiological indices showed a significant increase while sensory indices significantly decreased (p

Processing of fish lead to maintain the quality and nutritional value until they are consumed. The purpose of this study was to the effects of the cooking methods of boiling, frying, and roasting on changes of amounts of nutrients (moisture, fat, protein, ash, carbohydrates), the calorie value and minerals (calcium, phosphorus, sodium, magnesium, iron and potassium) of one of the selected marine fish (Carangoides ferdau) with recommended standard AOAC methods. Results showed that the amounts of nutrients, caloric value and minerals found different variations according to fish species and processing methods. The fat, ash, carbohydrates, calories and minerals values were reduced in roasted fish, and fat, protein, ash, carbohydrates, calories and minerals values were reduced in boiled fish, while moisture, ash and minerals contents were reduced in fried fish. In general, nutrients, minerals and caloric values of the studied fish were found less changes in frying method compared with other methods.

Nowadays attractiveness, marketability and food protection are the most important concerns of food industries. Application of edible and biodegradable coatings and sheets is of great interest for providing protection and beauty, and non-polluting for environment. The aim of this study was to optimize the formulation of squash-based edible sheet and to investigate the effect of carboxymethyl cellulose (CMC) (0.1-0.9 g), tragacanth (0-0.4 g) and glycerol (1.5-6.5 g) amounts on some physical properties of the resulted edible sheets, including oxygen permeability (OP) and water vapor permeability (WVP), moisture content, swelling capacity, solubility and water activity. Our results revealed that the increase in CMC content improved WVP of the sheets, whilst decreased their moisture content (P

In this study, the effect of three levels of temperature (30, 40, and 50°C) and seven amplitudes of pulsed ultrasound (0, 20, 30, 40, 50, 70 and 100%) on yield, kinetics and extraction thermodynamics of solvent extraction of black grape seed oil (Siah-Sardasht cv.) was evaluated. In addition, the kinetics of oil extraction were studied based on a second order reaction. According to the results, the highest oil yield of 16%, was obtained at several amplitude of pulsed ultrasound and at 50°C. In all treated and untreated samples, the extraction capacity (cs), extraction rate constant (k) and initial extraction rate (h) were increased by increasing temperature. The increase of cs and k in all treated samples by ultrasound was more than that of control ones and the identical results were found for h in most treated samples. The thermodynamic factors of the extraction process showed that samples treated by pulsed ultrasound have lower activation energy (Ea) and enthalpy ( Δ H) than control, and the same results were observed for frequency factor (A) in most treated samples. However, pulsed ultrasound-assisted solvent extraction had no effect on entropy ( Δ S ). Pulsed ultrasound-assisted solvent extraction increased kinetics in comparison to yield in the grape seed oil extraction.

The aim of this research was to study the physical and antioxidant properties of bacterial cellulose based active films containing Scrophularia striata extract. The effect of β-cyclodextrine (β-CD) and lamination process
was investigated on the properties of films. Results showed that the laminated films had the highest thickness. Water solubility of the films was increased by incorporation of the extract, but this property was decreased after lamination. Moisture uptake and water vapour permeability were decreased by β-CD inclusion and lamination process. a value, Yellowness index and total colour difference were increased significantly by addition of extract (p ≤ 0.05). But the effect of β-CD and lamination was not significant on colour properties. β-CD containing three-layer film had the highest tensile strength (15.11 MPa) and Young modulus (13945 MPa). Bacterial cellulose film containing extract showed a good DPPH radical scavenging activity (54.5%), but lamination process caused to decrease the antioxidant activity. Generally complex formation of extract with β-CD and also lamination was able to decrease the negative effects of extract on physical properties of bacterial cellulose film and to fabricate an active film with high antioxidant activity.

Use of coating treatment prior to osmotic dehydration can improve process performance by reducing solids uptake. In this study, the effect of coating-osmotic treatment on drying of apple cubes was investigated. So, the apple cubes (1 cm3) were coated in two concentrations (1 and 1.5% w/w) of carboxy methyl cellulose (CMC) and carrageenan solutions and osmotically dehydrated in different sucrose solution concentrations of 45 and 60˚ BX, for 150 minute. Then, coated apple cubes were dried in a hot-air drier at 70˚C to final moisture content of 20% (w.b) and the rehydration ratio of dried samples was measured. Our results revealed that the highest performance ratio was related to single-coated apple cubes with 1% solution of carrageenan, osmo-dehydrated in 60˚ BX and single and double-coated samples with 0.5% solution of CMC, osmo-dehydrated in 45˚ BX. Investigation of final drying showed that coated materials created a strong barrier against water removal and decreased the drying rate. Dried coating layers on apple cubes also prevented the samples from water absorption, and the coated apple cubes had a lower rehydration ratio than noncoated ones. We found that coating is effective only during osmotic process and it is not a good and efficient method for the final air drying.

In this study, the influence of various parameters such asinlet air temperature and maltodextrin concentration on physicochemical and functional properties as well as production efficiency of spray dried malt extract powder was investigated.A pilot-scale spray dryer used for drying. Process variables were inlet air temperature and maltodextrin concentration (DE=18-20). Maltodextrin asdrying aid in concentrations of 20, 30 and 40% (w/wwet weight of malt extract) was used. Inlet air temperature of 140, 160 and 180˚C in a co-current stream wasused. In all experiments, atomizer rotational speed, feed flow rate, feed temperature and atomizer air pressure were kept constant at 18000 rpm, 10 ml/min, 30±1˚C and 4±0.1bar, respectively. The least significant difference between means at p

In this research, an automatic solar dryer designed and constructed in order to use solar energy for agricultural crops drying. In this dryer water is used as heat transfer fluid. An experiment was carried out in order to investigate the effect of air flow velocity into the drying chamber at three levels (1.5, 3 and 4.5 m/s) on drying time and also the amount of shrinkage of three crops including grape, fig and plum. Results indicated that air flow velocity doesn’t have significant effect on shrinkage, whilst it showed significant effect on drying duration 1 percent level. So with increasing air flow velocity, drying duration is reduced. All tested products with solar dryer, were dried at lower time in comparison with to traditional drying, so drying duration for grape, fig and plum reduced to 49, 52 and 60 percent respectively. Also all the crops have low shrinkage in contrast to the traditional methods, so the shrinkage is reduced 13, 10 and 15 percent at grape, fig and plum respectively.

Today nano-liposomes are used extensively in all industries such as pharmaceutical and food. Nano-liposomes are formed when aqueous solution of phospholipids subjected to sufficient energy. In this study One-step method combined with ultrasonic waves was used to produce nanoliposomes. Quality characteristics such as particle size, entrapment efficiency and stability were measured.Combined experimental design was used to investigate the effect of different ratio of phospholipids, cholesterol and phytosterols powder (50-100%, 0-50% and 0-50%, respectively) and also the effect of sonication time (20, 25, 30, 35, 40 min) on the functional properties of nano- liposoes new formulation containing vitamin C. High sonication time led to the lowest standard deviation in particle size and increases the entrapment efficiency. In overall stability was increased by sonication time (The highest stability was observed in 35 and 40 minutes of sonication time), although this effect was different at various ratios of phospholipids, cholesterol and phytosterols. The results showed, although one-step method combined with low power ultrasonic waves was not effective to create ideal properties in nano-liposomes, cholesterol with phytosterols replacement, as well as using milk phospholipids and food grade solvent were efficient technique for producing nano-liposomes.

In the recent years, numerous studies have been focused on the production and applying of biodegradable polymers due to concern regarding the environmental pollution caused by plastic packaging materials, and also increasing consumer’s interest for improvement of quality and appearance of food products. Therefore, the aim of the present study was to evaluate the effects of methanolic pomegranate peel extract (PPE) separately and in combination with Ziziphora clinopodioides essential oil (ZEO) on the physical, mechanical and antibacterial properties of chitosan film. The analysis of the chemical composition of Z. clinopodioides essential oil was conducted by means of gas chromatography with mass spectrometry (GC-MS). Physical and mechanical properties of the investigated films including thickness, tensile strength, elongation at break, water vapour permeability (WVP) and color were examined. Antibacterial property of the films was evaluated against Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Listeria monocytogenes, Salmonella typhimurium and Escherichia coli O157:H7 using disk diffusion method. According to the results of the present study, the best antibacterial property (inhibition zone between 5.5-6.1 mm), highest tensile strength (59.6 MPa), thickness (0.081 mm) and elongation at break (41.6%), lowest WVP (21.3 g mm/kPa h m2) and also lowest lightness (L*= 45.41) were observed for chitosan film incorporated with ZEO 1% PPE 1%. The chitosan film incorporated with ZEO and PPE have shown good antibacterial, physical and mechanical properties which can be barrier against bacterial and chemical contamination in food products.

The aim of this study was to produce antimicrobial films based on carboxymethyl cellulose- chitosanoleic acid (CMC-CH-OL) containing different concentrations of ginger essential oil (GEO) in order to study the structural, physical, antioxidant, and antifungal properties of the films. The results of Fourier Transform Infrared Spectroscopy (FTIR) confirmed some hydrogen bonding formation between film matrix and GEO. Water vapor permeability (WVP) of the CMC-CH-OL film decreased from 5.28 ×10-7 to 0.99 ×10-7 g/m.h.Pa in the film incorporated with the highest concentration of GEO (GEO3). Based on the obtained results from WVP, contact angle and FTIR, it can be concluded that the addition of GEO with hydrophobic nature, led to an improvement in water barrier properties of films. The results of mechanical test revealed an increase in elongation at break (EB) and a decrease in tensile strength (TS) for the films containing GEO (p

A method of eliminating aflatoxins including aflatoxin M1 is microbial detoxification. Reports indicate that some strains of lactic acid bacteria family through adsorption of aflatoxin in their cell wall can be effective in removing them. In this study the ability of Bifidobacterium bifidum in the adsorption of aflatoxin M1 in probiotic yoghurt was assessed. Thus, probiotic and starters (108 cfu/ml) were inoculated to restructured skimmed milk without aflatoxin M1. Then, the samples were spiked by aflatoxin M1 in different concentrations (0.1, 0.5 and 0.75 ppb). The concentration of aflatoxin residue in supernatant of probiotic yoghurt and control samples after different storage times (1, 7, 14 and 21 day) was measured by ELISA method and the results were confirmed by HPLC. The results showed that although, both probiotic and starters was able to adsorb aflatoxin M1, the ability of Bifidobacterium bifidum was higher. Also, the probiotic and starters were able to reduce the higher amount of toxin, when the toxin concentration was low. The results of survivability of Bifidobacteriunm bifidum showed that during storage time, the number of surviving cells decreased 4 logarithmic cycles.

Coating fruit and vegetables with chitosan has some positive advantages for the long-term storage of them. Chitosan inhibits fungal growth and maintains the apparent quality of the fruit for a longer time. In this study, the effects of chitosan and cholid calsium in extending shelf life and maintains the quality of Indian jujube (Zizphus Mauritinia) were investigated. Fruits were immersion in chitosan (0.5, 1.5 and 2%) and cholorid calsium (1, 2.5 and 5%) for 5 min. then stored at 4°C for 25 days. Fruit quality attributes including weight loss, decay incidence, vitamin C, total soluble solids, firmness and color were evaluated an interval of five days. Results suggested that treatments (except calcium choloride 5%) reduces weight loss and decay also increases quality of color and firmness. However, there was no significant different between three chitosan coating concentrations in most cases. Both vitamin C and total soluble solids, were affected by chitosan and cholid calsium treatments. In general, for keeping appearance quality and improving storage life of jujube fruit, chitosane and cholorid calsium (2.5 %) is recommended.

Nougat is one of the Iranian traditional sweets which nowadays produced as traditional and industrial methods. Egg, is the most important ingredient in Nougat production, which is in addition of improving nutritive value, as a functional properties of proteins has a great influence on product texture. In this study, Box-Behnken design of response surface methodology was applied to survey effect of white egg content (6, 8 and 10%), xanthan gum (0, 0.1 and 0.2%) and gum arabic (0, 0.1 and 0.2%) on overrun, stability and density of the foam as well water activity, density and overall acceptability of the final product (Nougat). The results showed that using of gum had significant effect on overrun so that maximum level has been reached in the presence of 0.2% gum arabic without xanthan gum. Gum addition to Nougat mixture, increased foam stability with reduction of drainage. Water activity of treatments was increased along with hydrocolloid application but it was maintained in standard limit. The results of sensory evaluation showed that Nougats prepared with average values of both gum (0.1%), had higher acceptance. This study revealed that using hydrocolloids, improvement in the quality characteristics of Nougat is possible.

n this study, the effect of different drying methods was investigated on physicochemical characteristics, sensory properties and nutritional quality of strawberry and effective factors on the increasing of its shelf life. For osmotic dehydration treatment, temperature (35 and 45 °C), mixture of fructose and sucrose syrup concentration (70%(W/V) (20% fructose 50% sucrose)), calcium chloride (0.75 and 1.5% (W/V)), during 5 hours with 1 to 8 ratio of fruit to osmotic solution was used. The best treatment among the 8 different treatments was the treatment 8 (osmotic solution containing %50 fructose with %20 sucrose %1.5 calcium chloride and treatment time of 5 hours at 45°C) with respect to the lowest SG/WL which lead to better drying of strawberries in comparison with the other treatments and was known as the best treatment. Then, the best osmotic treatment with respect to physicochemical characteristics, and sensory properties was evaluated and compared to dried strawberry samples by microwave, hot air oven and control sample. The results showed the moisture content (%28, %37 and %18), pH (3.57, 3.15 and 3.19), acidity (% 0.042, %0.045 and % 0.044), Brix (%23, %15 and %26), total sugar (%15, %4 and %3), vitamin C (8, 13 and 19mg/100 g) and Anthocyanin (75, 72 and 86 mg/kg) in the strawberry samples dried by osmotic method, hot air oven and microwave methods, respectively. Dried strawberries using the microwave had lower moisture content, total sugar and a higher brix, vitamin C and anthocyanins than the samples dried with osmotic and hot air oven methods. On the other hand, from the viewpoint of sensory properties, dried strawberry using microwave and osmotic methods had better appearance, color, firmness and flavor in comparison with dried samples by hot air oven and control. Overall, dried strawberries using the microwave method had the lowest amount of moisture, vitamin C and the higher content of anthocyanins and sensory characteristics than the other drying methods. Therefore, in this study for producing of dried strawberries in comparison with the other drying methods, the microwave method was recommended.