Food Technology
Reza Farahmandfar; Samaneh Forghani
Abstract
IntroductionEdible oils constitutes a chief component of human diets in our daily life to supply essential fatty acids, energy, and nutrients to human. The nutritional value of edible oils varies depending on the type of oil, processing methods, extraction techniques, and storage conditions. Generally, ...
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IntroductionEdible oils constitutes a chief component of human diets in our daily life to supply essential fatty acids, energy, and nutrients to human. The nutritional value of edible oils varies depending on the type of oil, processing methods, extraction techniques, and storage conditions. Generally, edible oils are high in triacylglycerols with minor compositions. The presence of high amount of unsaturated fatty acids in the structure of triacylglycerol leads to a reduced shelf life of oils. This is associated to the undesired lipid oxidation that occurs when unsaturated fatty acids are exposed to light, oxygen, and heat. This is a major concern in food industry as it might result in undesired food quality deterioration involving reduction of nutritional components and off-flavors. The demand for nutritious and healthy animal and vegetable oils has been increased with a growth in population and economic progress. Therefore, researches for functional and nutritious edible oils has gained world attention on the technology to process edible oils. The use of ultrasound as a new technology in food processes is increasing due to its potential for changing materials and processing speed. This technique displays several advantages over conventional techniques in terms of time, energy consumption, and higher output. Ultrasonic processing is used in the food industry for numerous processes on high lipid containing food products in cutting, cooking, homogenization/emulsification, and microbial inactivation. The aim of this study was to investigate the effect of ultrasound time (0, 20, 40 and 60 min) on physicochemical properties of corn oil, soybean oil and kilka fish oil. Materials and MethodsCommercial kilka fish oil, corn oil and soybean oilwere purchased from local market. All of the chemicals and reagents used were analytical reagent grade. Each oil was poured at 250 ml Beaker and then treated with an ultrasonic probe at a frequency of 20 kHz for a specified period of time. Oil chemical and physical properties such as acid value (mg/g), peroxide value (meq O2/kg), oxidative stability index (h), thiobarbituric acid value (mg/kg), conjugated diene value (%), fatty acid composition, fourier transform infrared (FTIR) spectroscopy and color parameters (L*, a*, b* and ∆E) were determined. Data analysis was done using SPSS software and completely random design. Results and DiscussionThe results of this study showed that with increasing the duration of ultrasound, acid value, peroxide value, TBA value and conjugate diene value, increased and the induction period decreased. On the other hand, ultrasound treatment led to increase palmitic acid, stearic acid, oleic acid, saturated fatty acids (SFA) and monounsaturated fatty acid (MUFA), and decrease linoleic acid, linoleic acid (and palmitoleic acid, eicosapentaenoic acid and docosahexaenoic acid in kilka fish oil), polyunsaturated fatty acid (PUFA), polyunsaturated fatty acid/saturated fatty acids (PUSFA/SFA), unsaturated fatty acid/saturated fatty acids (USFA/SFA), Cox value in corn, soybean, and kilka fish oils. Ultrasound did not change the fourier transform infrared spectroscopy but did change some color parameters. Sonication caused an increase in L* (more lightness) of corn oil, a decrease in a* (more greenness) of soybean oil, an increase in b* (more yellowness) of corn and soybean oils, and a decrease in ∆E compared to control samples. Probably, ultrasound causes destruction and isomerization of the double bands of pigments and as a result changes in color indices. According to the results of this study, ultrasound treatment accelerated the oxidation and degradation of oils and as a result, changed some of the physicochemical properties of the oil, which varied according to the type of oil.
Food Biotechnology
Asad Abbaspour Anbi; Masoud Seidgar; Masoud Neyriz Nagadehi
Abstract
The present investigation was done to study the effects of Lactococcus lactis (L. lactis) subsp. lactis on the shelf life of the vacuum-packaged Oncorhynchus mykiss. Fish fillets were prepared and divided into 5 different treatment groups including control (distilled water), 2% and 4% supernatant, and ...
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The present investigation was done to study the effects of Lactococcus lactis (L. lactis) subsp. lactis on the shelf life of the vacuum-packaged Oncorhynchus mykiss. Fish fillets were prepared and divided into 5 different treatment groups including control (distilled water), 2% and 4% supernatant, and 106 CFU/g L. lactis subspecies lactis. The pH, Thiobarbituric Acid Reactive Substances (TBARS), Total volatile Nitrogen (TVN), and Peroxide Value (PV) of the fillets were determined on days 0, 5, 10, and 15 while maintained at 4˚C. Protein expression and destruction were analyzed using the SDS-PAGE. The organoleptic assessment was done using five expert sensory panelists. Contents of TBARS, TVN, pH, and PV were increased throughout the storage period (P <0.05). An increase in the concentration of supernatant caused a significant decrease in the content of TBARS, TVN, pH, and PV (P <0.05). The highest and lowest contents of TBARS, TVN, pH and PV on 15th day were belonged to the control (3.367±0.04 mg MDA/kg) and pure bacteria (0.70±0.02 mg MDA/kg), control (87.20±6.40 mg/100g) and 4% supernatant (40.79±0.61 mg/100g), pure bacteria (6.23±0.04) and 4% supernatant (5.44±0.07) and control (12.22±0.01 meq/kg) and 4% supernatant (3.08±0.06 meq/kg) groups, respectively. Protein destruction was lower in the fillet samples treated with pure bacteria and 4% supernatant. The highest scores of the odor, flavor, texture, and color were obtained for fillets treated with 4% supernatant, pure bacteria, pure bacteria, and 4% supernatant and pure bacteria, respectively. The results revealed that treating O. mykiss fillets with 4% supernatant and 106 CFU/g of pure L. lactis subsp. lactis can extend the shelf life of O. mykiss fillets.
Food Chemistry
Reza Safari; Seyed Vali Hosseini; Sharareh Firouzkandian; Soheyl Reyhani Poul; Mona Zamani
Abstract
[1]Introduction: One way to turn chicken waste into high value-added product is to produce fermented silage (biosilage). This product is superior to fish powder due to its characteristics such as high quality protein, probiotic bacteria and low price and can be considered as a suitable alternative for ...
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[1]Introduction: One way to turn chicken waste into high value-added product is to produce fermented silage (biosilage). This product is superior to fish powder due to its characteristics such as high quality protein, probiotic bacteria and low price and can be considered as a suitable alternative for feed industry. Silage can be produced from protein wastes by both acidic and biological methods. The acidic method of producing silage (acidic silage) uses a variety of organic and inorganic acids such as formic acid and sulfuric acid. In the production of biological silage, two methods of autolysis (using internal enzymes) and fermentation (using microbial starters) are used. Starters used for inoculation are mainly from the group of lactic acid bacteria. To produce silage, protein wastes are used, especially fish wastes. Since poultry waste has not been used for biosilage production in the country so far, the aim of the present study is to produce biological silage from chicken waste and evaluate the profile of amino acids and fatty acids in the biosilage. Materials and methods: Chicken intestine was prepared from meat production complex in Golestan province, Kordkoy city and also Simin Naz poultry industrial slaughterhouse in Sari and was transferred to the processing pilot of Caspian Sea Ecology Research Institute in the shortest time in cold container. During the biosilage production process, protein-degrading bacteria (containing protease enzymes such as gram-positive sporulated bacteria) and acid-producing bacteria (to reduce the pH of the suspension and accelerate the fermentation process, such as lactic acid bacteria) were used as initiator bacteria or microbial starters for intestinal digestion. The product was analyzed for protein, fat, moisture and ash according to standard methods. In this study, high performance liquid chromatography (HPLC) of Cecil model (Seri 200) was used for amino acids analysis. Samples were prepared for assaying amino acids profile in two stages including hydrolysis and derivatization and the results were expressed in grams per 100 grams of substrate. To determine the fatty acids composition of the biosilage sample, the fat was first extracted. In order to evaluate the profile of fatty acids, a Shimadzu model gas chromatography device was used and the results were expressed as a percentage. Results and discussion: The product produced contained about 60% protein and 21% fat. According to the results, the total of essential amino acids in the produced biosilage was 24.416, the total of non-essential amino acids was 30.959 and the total of essential and non-essential amino acids was 55.375 g per 100 g of substrate. Among essentialamino acids, the highest amount belonged to the amino acids leucine (7.334±0.45 g/100g) and valine (4.71±0.27 g/100g) and among non-essential amino acids, the highest amount belonged to glutamic acid (10.6±0.73 g/100g) and alanine (5.864±0.81 g/100g). It was also found that all essential amino acids except tryptophan are present in biosilage. Evaluation of biosilage fatty acids profile revealed that the total amount of saturated fatty acids (SFA) was 33.57%, monounsaturated fatty acids (MUFA) was 41.17% and polyunsaturated fatty acids (PUFA) was 24.36%. It was further found that in biosilage the total omega 3 was 2.07%, the total omega 6 was 22.91% and the sum of EPA and DHA was 2.06%.The profile of amino acids and fatty acids in the biosilage produced from chicken waste is almost the same as that of other products made from protein waste (such as fish meal, fish waste biosilage and hydrolyzed protein powder). This property, along with cheap production and high nutritional value, allows the use of biosilage obtained from chicken waste in the livestock, poultry and aquatics feed industry.
