جستجوی مقالات مرتبط با کلیدواژه « phenol compounds » در نشریات گروه « کشاورزی »

The sunflower (Helianthus annuusis) an annual verb from Astraceae genus that is grown as a firm bush. One of the oil extraction methods is the mechanical extraction (press) that is usually used in small scales. The main limitation of oil extraction using press is the high amount of residual oil in the meal. Therefore, recently some techniques, such as oil extraction using ultrasound and microwave, are taken into consideration in this case. The ultrasonic waves are some types of mechanical waves that have frequencies are higher than human hearing and microwaves are the non-ionized electromagnetic waves with frequencies range between 300 MH to 300 GH, and are placed between the radio and infrared ray in the electromagnetic spectrum. Regarding the fact that no research is performed in the case of applying the sequential pretreatment of extracting oil from sunflower seeds, for this reason in the current research it was tried to study the utilization of microwave-ultrasound pretreatment in extracting oil from sunflower seeds.

In performing this research the sunflower seeds (contain 38.5 percent oil) was prepared from Agricultural and Natural Resources Research Centre of Golestan Province. Then external materials such as weed seeds, sand and stones were separated by hand and transferred to the Food Industry laboratory of Azad Islamic University of Gonbad-e-Kavoos to perform experiments. At first the seeds were processed by microwave pretreatment with power of 540 watt and different times of process(0 to 120 seconds) and after this they were treated by an ultrasonic bath device with three different time levels(0 to 50 minutes) with stable frequency of 35 KH. After applying these treatments, the oil of seeds were extracted using the screw press with different speeds (11 to 57 rpm) and some experiments such as the efficiency amount of oil extraction, refractive index, color index, acidity and total phenolic compounds were performed on these oils. The response surface methodology, using the Box-Behnken design, was used to evaluate the constant parameters of study in comparison to the variable parameters.

Increase in the microwave and ultrasound time increased the oil extraction efficiency; although in the high ultrasound or microwave times with increase in these two parameters the amount of oil extraction efficiency decreased because of oil outlet ducts destruction. Increase in the oil extraction efficiency with increase in the microwave time can be related to more fracture of oil contained cells or is resulted from decomposition or destruction of protein compounds during treatment with microwave, on the one hand with increase in the ultrasound time some cavitations bubbles are created which have high collapse and explosion power and the force generated from bubbles explosion will lead to an increase in the cell membrane destruction. With increase in the rotational speed of press, the amount of extraction efficiency decreased a little because of reduction in the amount of pressure applied on seeds. The lowest amount of oil acidity that was measured on the basis of Oleic Acid was obtained in the conditions that no pretreatment was used in oil extraction and the rotational speed of screw press was 34 rpm. With increase in the microwave and ultrasound time, the amount of oils color index will increase. Also with increase in the rotational speed of press, the amount of color index increased too. The reason of increase in the amount of color index with increase in the microwave and ultrasound time and also with the rotational speed of press can be attributed to more release of chromogenic compounds in the extracted oil. All of the experiment variables (microwave and ultrasound time and rotational speed of screw press) didn’t have any influence on the refractive index of oils and its amount were equal to 1.0471 for all of the measured and evaluated samples. With increase in the microwave and ultrasound time, the total phenol of oils was increased at first and decreased then. Also optimization of this process indicated that if the microwave time is 33.71 seconds, the ultrasound time is 28.38 minutes and the rotational speed of screw press is 11 rpm, they will lead to obtain the regarded aims. At last it can be said that applying the microwave-ultrasound pretreatment can be propounded as an appropriate pretreatment in the oil extraction industry. With increase in the microwave and ultrasound time, the total phenol of oils was increased at first and decreased then. Also optimization of this process indicated that if the microwave time is 33.71 seconds, the ultrasound time is 28.38 minutes and the rotational speed of screw press is 11 rpm, they will lead to obtain the regarded aims. At last it can be said that applying the microwave-ultrasound pretreatment can be propounded as an appropriate pretreatment in the oil extraction industry. With increase in the microwave and ultrasound time, the total phenol of oils was increased at first and decreased then. Also optimization of this process indicated that if the microwave time is 33.71 seconds, the ultrasound time is 28.38 minutes and the rotational speed of screw press is 11 rpm, they will lead to obtain the regarded aims. At last it can be said that applying the microwave-ultrasound pretreatment can be propounded as an appropriate pretreatment in the oil extraction industry.With increase in the microwave and ultrasound time, the total phenol of oils was increased at first and decreased then. Also optimization of this process indicated that if the microwave time is 33.71 seconds, the ultrasound time is 28.38 minutes and the rotational speed of screw press is 11 rpm, they will lead to obtain the regarded aims. At last it can be said that applying the microwave-ultrasound pretreatment can be propounded as an appropriate pretreatment in the oil extraction industry.

Recently, environmentally-friendly materials, ideally those able to be obtained from bio-based resources and presenting biodegradable characteristics, are used to improve quality and biosafety of horticultural products. Fruits of sweet cherry (Prunus avium ‘Siah Mashhad᾽) were coated by galbanum gum (0, 1, 2, and 3%w/v), cumin essential oil (0, 100, and 200 µL L-1), and calcium chloride (0 and 1%w/v). The coated fruits were then kept in a storage at 2±1°C with 90-95% relative humidity for 30 days and one additional day at 20ºC. After that, the quality of fruits was evaluated. All concentrations of experiment factors, increased the activity of catalase and peroxidase enzymes 15 days after storage and retained these properties until storage. Also these treatments slowed the rapid reduction in ascorbat-peroxidase enzyme activity, acid ascorbic content and general acceptance. 1 and 2%w/v gum galbanum composed with 1%w/v calcium chloride/200 µL L-1 cumin essential oil cause a temporary increase in total antioxidant and phenol 15 days after storage and retained these features until the end of the shelf life. 1%w/v galbanum gum combination with 1%w/v calcium chloride/ 200 µL L-1 cumin essential oil can be used as a suitable alternative for chemicals in maintaining sweet cherry quality and shelf ilfe.

One of the most important characteristics of fruit crops is susceptibility to decay and quality reduction during storage life. Crops with higher antioxidant capacity are tolerant to stress and have greater nutritional quality and storage life. Hence, to investigate the antioxidant capacity of two grape cultivars Ghezel uzum and Red hosseini a factorial experiment with 3 replications was carried out as a Randomized complete block design. Results showed that the percentage of weight loss in Ghezel uzum cultivar was 1.5 fold greater than Red hosseini cultivar. Berry quality traits such as total soluble solids, pH, the amount of electrolyte conductivity and fruit taste index were increased while titrable acidity, carotenoid, chlorophyll a and b, anthocyanin, vitamin C, total phenol and the amount of antioxidant activity were decreased during storability in both cultivars. Ghezel uzum had more carotenoids than Red Hosseini (2.6 fold) but the extent of decreases in pigment concentration in Red hosseini was lesser than that of the other cultivar. In contrast the amount of antioxidant capacity (88.20% and 17.38% in skin and pulp, respectively), total phenol (204.4 and 2.11 mg 100gFw-1 in skin and pulp, respectively) and chlorophyll a and b (1.13 and 3.9 µg Kg-1, respectively) was greater in Red Hosseini cultivar compared to Ghezel uzum cultivar. It may be concluded that the Red hosseini cultivar has a greater capability in preserving its quality characteristics at the end of storage life, compared to other cultivar.

Chitosan is a glucosamine polysaccharide deacetylated form of chitin species and could be used as a biotic elicitor to improve secondary metabolites. In order to study the effect of chitosan on malondialdehyde (MDA), antioxidant enzymes activity such as catalase (CAT), superoxide dismutase (SOD) and ascorbate peroxidase (APX), phenol compounds, chlorophyl a, b, carbohydrate and proline in ajowan, this study was conducted as a randomized complete block design (RCBD) with three replications at Biocenter of University of Zabol. Chitosan had four levels (0, 100, 150 and 200 ppm). In comparison with the control, the results showed that malondialdehyde (MDA), antioxidant enzymes activity such as catalase (CAT), superoxide dismutase (SOD) and ascorbate peroxidase (APX), phenol compounds, chlorophyl a, b, carbohydrate and proline increased to 72.96, 92.22, 91.74, 92.61, 86.35, 73.52, 81.16, 94.6 and 91.4% respectively, while increasing the amount of chitosan to 200 ppm. It seems that in concentrations higher than 100 ppm, chitosan, as a biotic elicitor, increases antioxidant enzyme activity and secondary metabolites production in four stages of ajowan.

Peach has high nutritional value that can be used fresh-able or processed. This study¡ was conducted to examin the effects of different levels of methyl jasmonate (0¡ 100 and 200 mg l1)¡ salicylic acid (0¡ 150 and 300 mg l-1)¡ and their interactions on growth¡ yield¡ fruit quality at harvest time and postharvest quality and shelf-life of „Elberta‟ peach. Thus¡ trees sprayed by treatments in two stages of green tip and pink tip of bud¡ in a split-factorial experiment within a randomized complete block design with 4 replications. At harvest time¡ many of the biochemical and quantitative characteristics of fruit such as ripening delay¡ firmness¡ total soluble solid¡ organic acids¡ pH¡ vitamin C¡ fruit water percentage¡ dry weight percentage of fruit¡ reducing sugars¡ anthocyanin¡ phenol content were studied. Generally¡ the results showed that spraying at both stages increased biochemical and quantitative characteristics of fruits compared with control and between treatments. Methyl jasmonate (200 mg l-1) combined with salicylic acid (150 mg l-1) had the highest effect on improving quantitative characteristics of fruits. Trees treated with chemical had shown greater growth improvement of fruit quaility compared wit pink tip stage at green tip stage.

The use of natural extracts as one of good antioxidant source is increasing to improve fish quality. The present study aims at investigating antioxidant effect of orange peel extract on the quality of common carp fillet during refrigerated storage (4°C). Fish fillets were treated by 0، 1 and 5 % concentration of orange peel extract، packed and then stored in refrigerator. Chemical parameters (pH، peroxide value (PV)، thiobarbituric acid (TBA) and total volatile bases nitrogen (TVB-N)) and sensory analysis (texture، odour، taste، color and total acceptance) were measured by panelists on 0، 3، 6، 9، 12 and 15 days. The pH value increased during storage that was more in control (p< 0. 05). The amount of PV، TBA and TVB-N were significantly increased in the all of treatments، so that the values of control، 1 and 5 % reached to 14. 8، 12. 2، 10. 2 meq o2/kg fish fat and 0. 99، 0. 78، 0. 59 mg malonaldehyde/kg fish flesh and 33. 3، 30. 5، 22. 6 mg N2/100 g fish flesh at the end of storage respectively. The increase of values in 5 % was less than other treatments (P< 0. 05). Results of sensory analysis indicated significant reduction in sensory characteristics of fillets during storage. According to results of this study، fillets treated by 5% extract are consumable until end of storage in comparison with other treatments.