جستجوی مقالات مرتبط با کلیدواژه « پوست کیوی » در نشریات گروه « صنایع غذایی »

Nowadays, the use of natural antioxidants to increase the shelf life of foods has increased. In this study, kiwifruit peel extract was obtained by probe sonication at two intensities of 50 and 80% and ultrasonic bath. The free phenolic of bath ultrasound (265.88 mg/g), and bonded phenol in two intensities 50% (60.36 mg /g) and 80% (63.83 mg/g) had antioxidant activity in DPPH free radical scavenging method. Nano-encapsulated phenolic compound was performed using garden cress seed gum. All three nano-encapsulated phenols had nanometer size (146.5-172.3 nm) and negative zeta potential. In order to compare the antioxidant activity of free and bonded phenolic compounds nano-encapsulated phenols at 800 ppm and synthetic antioxidant TBHQ at 100 ppm were added to soybean oil without antioxidant. The samples were stored at 60 ° C for 40 days and tests were performed on the samples for 8 days intervals. The results showed that with increasing storage time, the amount of release and sedimentation of phenolic compounds increased. Oxidation of oil increased with storage time. The lowest and highest oxidation rates were observed in TBHQ and control samples, respectively. The use of bonded phenol at 80% intensity due to no statistically significant difference (p>0.05) with the sample containing synthetic antioxidant can be used as a natural antioxidant to extend the shelf life of the oil.

These days, food consumers pay more attention to the quality and health of food and therefore there is a high demand for healthy and low-calorie food products, So in this study, the effect of stevia and kiwi peel extracts on the shelf life of sponge cake was investigated. Stevia extract was added to the sponge cake formulation at two levels of 0 and 0.6% and kiwi peel extract at four levels of 0, 0.5, 1 and 2%. The results showed that free fatty acid, peroxide value, and count of mold and yeast had an increasing trend over time so that different treatments on days 21 and 0 of the highest and lowest Mean free fatty acid (0.422, 0.204), peroxide value (2.48, 1.17) and logarithm of mold and yeast (6.17, 1.43) were respectively. Therefore, at the end of the period, the highest increase was observed in the control sample (T1) and the lowest increase was observed in the treatment containing 2% kiwi peel extract and 0.6% stevia extract (T8). The results of sponge cake pH showed that different treatments on days 0 and 21 had the highest and lowest mean pH, respectively. The results of organoleptic evaluation of general acceptance showed that treatments containing 1% and 2% kiwifruit peel extract (T3 and T4) had the highest score and treatments containing 0.6% stevia extract (T5) had the lowest overall acceptance score, respectively. Therefore, treatment with concentrations of 2% kiwi peel extract and 0.6% stevia extract (T8) could well increase the shelf life of sponge cake for 21 days compared to the control sample and was selected as the optimal treatment.

sheep meat has a high potential for degradation due to high protein, fat and moisture. In this study, the antioxidant and antimicrobial effects of kiwi peel extract in two types of common and nano coatings based on basil seed gum, perfoliatum seed gum and their composition in increasing shelf life of sheep meat were investigated. Hydroalcoholic extracts of kiwi peel were obtained using ultrasound assisted technique the total phenolic content and total flavonoid  being 342.0 ± 3.12 mg GA/g E and 6.39 ± 1.02 mg QE /g E respectively. Different concentrations of kiwi peel extract (500, 1000, 1500, 2000 and 2500 ppm) showed high antioxidant activities due to phenolic and flavonoid compounds in both DPPH free radical scavenging and beta carotene: linoleic acid bleaching assay. The minimum inhibitory concentration and the minimum bactericidal concentration of the extract for Staphylococcus aureus, Pseudomonas aerogenes and Escherichia coli were determined that 2000 ppm of extract used in coating. The particle size of the nano-coatings was in the range of 81.53 to 176.15 nm, and the zeta potential of all nano-coatings was negative. Meat samples were kept at 4 ° C for 25 days and peroxide value, thiobarbituric acid value and total count of bacteria were performed at 5-day intervals, indicating that the chemical and microbial growth rates in control sample were higher than coated samples. The use of nanotechnology in reducing the size of coating resulted in improved antioxidant and antimicrobial properties. According to the results of this study, the composite nano-coating of basil seed gum: alyssum seed gum containing kiwi extract of 2000 ppm can be used in meat packaging industries.

The peel of fruits, in particular, are an abundant source of natural compounds and contain the higher amount of phenolics compared to the edible portions. Ultrasound-assisted extraction (UAE) is an ideal extraction method capable of producing high quantities of bioactive compounds with a shorter extraction time. Probe and bath systems are the two most common ways of applying ultrasound waves to the sample. Probe sonicators are constantly in contact with the sample and make reproducibility and repeatability difficult. In addition, the risk of sample contamination and foam production is higher. Bath sonicators can act on a range of samples simultaneously and allow for higher reproducibility. Kiwifruit belongs to family Actinidiaceae and genus Actinidia. Kiwifruit is characterized by a high content of vitamin C and other useful compounds such as vitamin E, flavonoids, and minerals. Phenolic compounds present in Kiwifruit peel are catechin, epicatechin, chlorogenic acid, caffeic acid, coumaric acid, and rutin. Several studies have been done on the extraction of various plants with ultrasonic waves. Most of the research on the extraction of plant extracts by ultrasound-assisted under various conditions of parentage such as time, solvent, temperature, and intensity of the sound obtained matched with other traditional methods of extraction and different studies have shown that there was never study on the effects of ultrasound bath and probes under the same conditions (temperature, solvent, time and frequency) on obtained extract and comparison of both two methods has been done. The aim of this study was comparing the antioxidant activity of Kiwifruit peel extract (KPE) obtained by two extraction methods ultrasound bath and probe techniques in same conditions temperature, solvent, time and frequency. Hayward Kiwifruit variety was purchased from gardens in Tonekabon City. The peels were dried in the shadow at 25-27˚C, and then they were finely ground in a laboratory grinder. The dried peels were pulverized and sieved through a 40-mesh sieve to obtain the powdered samples. The dry plant material was then packed in the plastic bag and stored in a freezer at -18˚ C. 10 g of Kiwifruit peel powder was extracted with 100 mL of a mixture of ethanol–water 80% (v/v) at two methods Ultrasound Bath Extraction by using a 25 kHz ultrasonic system (model Elma Sonic S30H, Germany), temperature (45°C), time (20 min) and Ultrasound Probe Extraction by using a 25 kHz ultrasonic system (model VCX 250, Sonics & Materials, Inc., USA), temperature (45°C), time (20 min), amplitude of 45% with a probe of 1 cm in diameter was used. After obtaining extracts, an efficiency of extraction, total phenolic and flavonoid compounds, scavenging activity of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, and ferric reducing antioxidant power (FRAP) assay were measured and concentration of 0.1 mg/ml of synthetic antioxidant TBHQ was as the control sample. All data were reported as mean ± standard deviation of three replicates. The results were compared by analysis of variance (ANOVA) using SPSS for Windows [version 16]. Mean differences were significant for extraction efficiency, total phenolic and flavonoid compounds based on T-test (binary comparison) and other tests based on Duncan's test at 0.05. Charts were drawn with Microsoft Excel version 2016. These results showed that the highest amount of phenolic compounds, flavonoids, extraction efficiency, and antioxidant activity were obtained in UPAE-KP. In both extraction methods, with increasing KPE concentration, DPPH free radicals scavenging and ferric reducing antioxidant power also increased. The concentration of 2 mg/ml UPAE-KP extracted the highest percentage of inhibition (94.11%) in all of the concentrations of the extracts in two methods. UPAE-KP at concentrations of 1.5 and 2 mg/ml and UBAE-KP at a concentration of 2 mg/ml showed better performance in scavenging free radicals than TBHQ. Among the extracts, IC50 UPAE-KP was 0.2±0.06 mg/ml which was significantly different from UBAE-KP (P<0.05). TBHQ at a concentration of 0.1 mg/ml (with a percentage of inhibition of 88.04±0.5) showed a better radical inhibitory activity than the low concentrations of Kiwifruit Peel extracts. UPAE-KP with a lower IC50 (0.09±0.07) showed more reducing antioxidant power than UBAE-KP. TBHQ at a concentration of 0.1 mg/ml (with an absorption rate of 304/1) had greater reducing antioxidant power than the Kiwifruit Peel extracts at all concentrations except the concentration of 2 mg/ml UPAE-KP. In this study, the extraction of KPE with both ultrasound methods was acceptable in terms of efficiency and antioxidant activity, with the difference that the probe superior to the ultrasound bath. Therefore, according to the results, KPE was competitive with TBHQ activity. KPE can be used as a useful source to provide natural antioxidant, and the probe compared with the ultrasound bath is a better way of extracting the KPE phenolic compounds.