جستجوی مقالات مرتبط با کلیدواژه « روغن پالم » در نشریات گروه « صنایع غذایی »

One of the common adulterations in milk and dairy products, is the addition of low-priced vegetable oils such as palm oil in order to increase the profitability of products. Therefore, there is an urgent need to develop accurate, fast and reliable identification techniques to protect consumers against this type of adulteration. The aim of the present study was DNA barcoding with real-time PCR as a reliable method for detecting palm oil fraud with levels of 2, 3, 4, 5, 10, 30, 50 and 100 % and positive and negative control samples in yogurt. According to the results, the highest and lowest concentrations of DNA extracted belonged to the palm oil sample of 100 % and 3% , respectively, while among all samples, the concentration of DNA extracted in sesame oil and then in the control oil sample was lower. It was determined from other samples. The lowest and highest adsorption rates (10mm) between the samples were control oil (excluding palm) and 100 % palm oil, respectively. There was no significant difference in absorption rate between 4%, 5% and sesame oil samples. The range for detecting palm oil adulteration was from 0.05% to 100% palm oil. LOQ and LOD were 0.1 % and 0.05 % of palm oil, respectively.

Olive oil due to its unique properties and characteristics in terms of nutrition has a very high and well-known position in various societies, but due to the high price of this product is always threatened by all kinds of fraud. Tocopherols and tocotrienols are present in small amounts (about 0.35%) in fats and oils. In this study, the fraud of adding vegetable oils (palm, soybean and corn) to olive oil was investigated by comparing the profiles of tocopherols and tocotrienols using HPLC (High-Performance Liquid Chromatography). The mixture statistical design was used to design experiments related to the measurement of tocopherols. After dissolving in n-hexane, the counterfeit oil samples were injected into HPLC with NH2 column chromatography and 294 and 320 nm fluorescence detectors, respectively, for stimulation and diffusion to identify and analyze tocopherols and tocotrienols. Among all tocopherols and tocotrienols, alpha-tocopherol was predominant in olive oil. Therefore, if combined with other oils, the initial composition of tocopherols changes. Among the oils added to olive oil, palm oil had a very significant effect on the peak area of the tocotrienols. Palm and corn oil had a significant effect on the beta-tocopherol peak. In the mixture of olive oil with corn and soybean oil, the amount of gamma-tocopherol increased significantly. Soybean oil had a significant effect on the peak of delta-tocopherol. Therefore, it can be concluded that delta-tocopherol is an indicator of fraud in adding soybean oil to olive oil. The results showed that there is a significant relationship between the amount of tocopherols and tocotrienols and the fraudulent addition of palm, soybean and corn oils to olive oil. Therefore, the proposed method is a suitable method for identifying and determining fraudulent olive oil.

Physical instability and cohesion of fat-based filling in baking products have long been one of the major problems in the food industry. Since the continuous phase of these fillings is fat, the desired thermal stability can be achieved by selecting the appropriate oil. Palm oil and its products are oxidation resistant and stable for a long time at high temperatures. In this study, in order to achieve heat stable oil in the formulation of cake filling, palm oil was fractionated at two temperature levels of 5°C and 17°C, by solvent method and using pure acetone, and physical chemistry tests including determination of combination of fatty acids, solid fat content, thermal behavior analysis, melting point, saponification index, iodine index, peroxide number, acid number were performed. Palm olein oil of 17°C was used in the filling formulation and the effects of cooking temperature and storage time on the sensory, physical and rheological properties of the filling (hardness, cohesion, adhesion, gummy state) were evaluated. By reducing the fractionation temperature, in stearin fractions, the percentage of unsaturated fatty acids decreased and the percentage of saturated fatty acids increased. The palm-olein fraction of 17°C was suitable for using in formulation of filling due to fast melting profiles and relatively high solids content in 20°C, and uses in formulation of filling have affected all texture factors. Temperature and time alone did not make difference (P> 0.05) in the rheological, physical and sensory characteristics of the filling, but at the same time caused a difference (P ≤ 0.05) in the factors mentioned. The palm olein fraction of 17 °C in the formulation produced a thermal stability in the cake.

Due to unique chemical composition,palm oil has been extendedly used in food products such as margarine, shortenings, cooking oils and specially frying oils.In this research, physicochemical properties and oxidative stability of palm-free frying oil formulated by colza, corn and sunflower oils were investigated. The portions of produced frying oils containing palm oil, corn oil, colza oil and sunflower oil were respectively from left to right 0:20:20:10 for treatment 1, 0:60:30:10 for treatment 2, 0:50:40:10 for treatment 3, 0:40:50:10 for treatment 4 and 0:30:60:10 for treatment 5. Obtained results showed, Iodine value increases and total saturated fatty acids (SFA), saponification value and smoking point decreased with the remove of palm oil from formulation. In terms of physicochemical properties, the results indicated that in palm-free samples (treatment 2 to treatment 5) with the increase of colza oil and decrease of corn oil in formulation, SFA, smoking point, saponification value decreased and iodine value increased. Investigation on oxidative stability in palm-free frying oils indicated a decreased Rancimat test and an increased peroxide value, AV and Anisidine value. Regarding oxidative stability evaluation, an increased acid value and Anisidine value and decreased Rancimat test were observed, although no significant different in peroxide value was distinguished in palm-free sample with the increase of corn oil and decrease of colza oil. Consequently, owning to obtained results blank sample (palm-containing sample) is of the best physicochemical properties and oxidative stability. In palm-free samples (treatment 2 to 5), treatment 5 showed more proper results than others.

Due to the noticeable use of palm oil as an additive in dairy industry, and the increased interest of consumer in the foods with antioxidant value, the palm oil was used in the entrapment of tea catechin, and its efficiency was compared with that of the milk fat. In the current research, the effect of type of oil phase (palm oil and milk fat), different ratios of span 80 surfactant to lecithin (0.5- 2) and varied RPMs (600-900 rpm) were investigated on the encapsulation of catechin by spontaneous emulsification method, upon which pH, creaming index, electrical conductivity, brix, refractive index, particles size and antioxidant activity were measured. The obtained results showed that an increase in PRM caused to a rise in creaming index in all samples, in particle's size in nano capsules with milk fat, and in refractive index and antioxidants activity in nano capsules with palm oil, while the increased PRM resulted in a decrease in particle's size in nano capsules with palm oil. In addition, increasing the ration of span 80 to lecithin led to increased creaming index and reduced pH and electrical conductivity in all samples, whereas it did not bring about a significant change in particle's size. Surprisingly, the Brix of nano capsules with palm oil was more than that of nano-capsules with milk fat. Generally, the palm oil nano capsules containing catechin produced from palm oil had proper features compared to the milk fat nano capsules containing catechin.

Main objective of this research was production of high fat yoghurt by partial or complete substitution of milk fat with palm oil. Three different types of high fat yoghurts, including yoghurt containing only 8% milk fat (control) yoghurt containing 4% milk fat and 4% palm oil, yoghurt containing 8% palm oil were produced. Samples kept in 4°C for 28 days and their physicochemical properties determined at the interval of 7 days. The results of statistical analysis showed that the treatment and the storage had significant difference (P0.05). Substitution of milk fat with palm oil reduced the levels of saturated fatty acids and short chain fatty acids while the amount of saturated fatty acid of Palmitic acid and unsaturated fatty acids of oleic acid and Linoleic acid showed a significant increase (p

Mixtures of palm and sunflower oils with different compounds of 80:20, 60:40, 50:50, 40:60, 20:80 were inter-esterified. For this purpose a special stabilized lipase (Lipozyme TLIM) was used and the physicochemical properties were determined as following: free fatty acids content, peroxide value, iodine value, slip melting point, solid fat content, P-anisidine value, soap, oxidative stability at 110 0C, and the profile of fatty acids on the primitive blends and final samples after esterification processes. The inter-esterification reactions were done by addition 6% enzyme to blend and reactions were done at 70 0C for 4 hours. Esterification caused to decrease in oxidative stability, solid fat content, slip melting point, peroxide value and increase in P-anisidine value, soap and free fatty acids. The blend of palm and sunflower oils with different percentages had saturated and unsaturated by and from fatty acids in ranges of 37.6-52%, 48-62.4% respectively. Loss of oil is the most important issue in inter esterification process of oils and fats; so the optimization of the process was studied to produce the minimum free fatty acids content and to minimize loss of the oil. The optimum condition for minimizing the fatty acid in oil under the condition at 65 0C and using 7.5 percent enzyme for 4.5 hours reaction was obtained. Also the statistical studies of fatty acids blends before and after reaction for 50:50 ratio of the used oils showed that the esterification process has no effect on fatty acid structure of the blends.

Possibility of replacing whole soy flour for chocolate fat in chocolate production and its impact on textural, rheological and sensory properties of low fat chocolate was explored. For doing this, whole soy flour in 5 levels (0, 2,4,6,8 percent) and two refining times (105 and 135 minutes) was employed. Results indicated that longer refining time gave rise to reduction in particles size and increase in hardness of chocolate. With increasing refining time from 105 minutes to 135 minutes, hardness showed an upward trend which rose from 7100g to 8180g. Casson yield value and Casson viscosity ranged between 9.02 Pa to 35.09 Pa and 2.55 to 5.99 (Pa.s), respectively. Data revealed that whole soy flour up to 4% can be successfully substituted for chocolate fat, without causing significant difference in textural, rheological and sensory properties of chocolate samples (P