ابوالفضل گلشن تفتی

The aim of the present research is to maintain quantitative and qualitative properties, including vitamins and additional moist phenolic compounds during storage. Mazafati dates was treated at five levels with chitosan extract of 4000 ppm thyme, chitosan with thyme extract of 6000 ppm zein with 1000 ppm clove extract and using ozone gas . After packaging, Date samples were stored in a cold room under completely hygienic conditions. The tests of each treatment (including vitamin B2 and B3, phenolic compounds, flavonoids and antioxidant activity) were performed every two months on three replicates. Result showed very low level of vitamin B3 in Mazafati dates, so in the calculations, the vitamin B3 was considered to be zero. The highest amount of vitamin B2 in the treated samples, was related to ozone treatment after 6 months storage and chitosan + thyme 4000 ppm after 4 months storage. In most treatments, the storage time partially increased the amount of vitamin B2. The amount of riboflavin in date varieties was between 0.13 and 17.5. During the storage period, the edible layers and ozone gas had a positive effect on the protection of phenolic compounds. Based on the comparison of the average results, chitosan treatment + 4000 ppm thyme oil extract and chitosan + 6000 ppm thyme treatment showed high phenolic compounds six months after storage

In this study, heat treatments (Temperatures of 50 oC, 60 oC and 70 oC for 1h & 2 h in 75-80% RH) and low temperatures (0 oC and -5 oC for 24 h and 48 h) were used in controlling of storage pests in Ghasb and Shamsaei date varieties. After treating and packaging, the date varieties were stored in cold room and also at ambient temperature for 6 months and the rate of pest infestation, microbial and chemical analysis were carried out after 2 interval months of storage. Oligonychus afrasiaticus and Ephestia figulliella were reported as important pests of Ghasb and Shamsaei dates in Shahdad region. Temperature of 70 oC for 2 h was the most effective for disinfestation and reduction of microbial load in Ghasb and Shamsaei date fruits. The rate of pest infestation and acidity (as lactic acid) in the samples of stored at ambient temperature increased during storage. The samples stored in cold room had not only the lowest rate of acidity and pest infestation but also the rate of infestation and acidity significantly reduced in these samples during storage. Cold room was effective in preventing the activity of microorganisms and pests in Ghasb and Shamsaei date varieties.

Strawberry (Fragaria x ananassa) as one of the most widely consumed fruits in the world is produced in 73 countries worldwide (Muzzaffar et al., 2016). Strawberry is mainly grown in Kordestan, Golestan, Mazandaran and Gilan provinces of Iran with Kordestan, Paros, Queen Eliza, Selva, Camarosa and Pajero as the most important cultivars. Since strawberry is very perishable fruit, requires careful harvesting and handling to maintain its quality after harvesting. Considering its sensitivity to physical injuries and fungal invasion besides rapid softening and susceptibility to rots, strawberry fruit has a short postharvest life. Gray mold, caused by Botrytis cinerea is considered as the most important strawberry disease with many negative impacts on ripening, marketing and postharvest life of the fruit (Abd-Alla et al., 2011). No strawberry cultivar is resistant to gray mold. The pathogen is able to infect stored strawberries because mycelia spread from infected fruit to adjacent healthy fruit. Several technologies have been used to reduce postharvest losses and extend the storage life of strawberries. These technologies include chemical control, low temperature storage, control atmosphere packaging, essential oils and irradiation (Marjanlo et al., 2009; Maraei and Elsawy 2017). Most of these techniques could be effective for shelf life extension of strawberry fruit. However, many reports documented harmful effects of chemical fungicides on human health and environment besides causing fungi resistance. Some compounds and methods may also have adverse effect on color, flavor or texture of the fruit. Thus, in the past few decades, research has focused on the use of safe and natural preservatives. It was reported that the storage life of strawberry fruit increased by application of cumin essential oil (Marjanlo et al., 2009). Among the various alternatives, metal oxides such as magnesium oxide and zinc oxide are catching the attention of scientists worldwide. These oxides render antimicrobial activity with higher stability in comparison to organic antimicrobials. Zinc oxide nanoparticles are less toxic than other nanoparticles such as silver nanoparticles. In addition, they are safer for human beings in comparison to other metal oxides (Al-Naamani et al., 2018). Al-Naamani et al. (2018) proved the efficiency of chitosan-znic oxide nanocomposite coatings in extending the shelf life of the packed okra. The application of nanocomposite film containing 2% zinc oxide nanoparticles maintained the qualitative characteristics of Mazafati date during cold storage (Sadeghipour et al., 2019). The aim of this study was to investigate the effect of different concentrations of zinc oxide solution on quality and shelf life of strawberry fruits (camarosa cultivar) during ambient and cold storage.

Zinc oxide solution with brand name Eimen Jav was purchased from Eimen Novin Pushan Pak Company. “Camarosa” strawberries at commercial maturity stage were harvested from a greenhouse located in Hashtgerd, Alborz province, Iran and then transported to Agricultural Engineering Research Institute. Fruits of uniform size without any defect were selected and used for the experiments. Strawberries were dipped in the solution at different concentrations (0.31%, 0.63%, 0.94%, 1.25%) for 1, 2 and 3 minutes. Then, the fruits were air dried at room temperature, put in plastic fruit boxes and stored at ambient temperature (25 oC, 30% RH) for 6 days and cold room (4 oC, 85-90% RH) for 21 days. The sampling was done on day 0, 2, 4, and 6 through ambient temperature and on day 0, 7, 14, and 21 through cold storage. Decay percent was calculated by visual observation of each sample. Fruits with visible brown spot and softened area were regarded as decayed fruit. Texture evaluation was performed by a texturometer. Firmness values of each individual strawberry were measured at two points of the equatorial regions using a 5 mm diameter probe and 500 load cell, at 2 mm/sec-1. Total soluble solids content was measured using a refractometer, Titratable acidity (TA) was calculated by titrating of clear juice of strawberry against 0.1 N NaOH solution and the results were expressed as citric acid %. Ascorbic acid content was determined by using 2,6-dichlorophenol indophenols titration method. A five-point hedonic scale was used for conducting the sensory evaluation of the samples. A panel of 15 judges was selected to evaluate the treatments for various sensorial parameters like appearance, texture, taste, and overall acceptability. Plain water was given to the judges to rinse their mouth between the evaluations of samples. The study was conducted as a factorial experiment in randomized complete design. All determinations were carried out in triplicates and the means were separated by Duncan Multiple Range test. All statistical tests were done by SPSS ver. 22 and were meaningful at 5%.

Ascorbic acid content was significantly affected by zinc oxide solution at different concentrations and immersion times. The ascorbic acid value of the control was significantly lower than the treated fruits. Ascorbic acid content decreased through the storage time as observed in all treatments and the control. Zinc oxide treated strawberries at 0.31% concentration for 3 minutes had higher firmness values and better qualitative characteristic with increased shelf life up to 2 weeks during cold storage. Additionally, this treatment reduced fungal decay up to 50% compared to the control during cold storage. Zinc oxide solution at 0.63% concentration for 3 minutes increased the shelf life of strawberry fruits up to 48 hours under ambient temperature. In this condition, fungal decay reduced up to 70% as compared to the control. Zinc oxide solution had no effect on sensory attributes of the fruits.

This study showed that strawberry fruits treated with zinc oxide solution (Eimen Jav solution) at recommended concentration and under storage in cold room had better quality and less decay than the control. The results introduce zinc oxide solution as a useful method for maintaining strawberry quality and extending its storage life.

Green and blue mold rot diseases caused by Penicillium digitatum and Penicillium italicum are the most important postharvest diseases of citrus fruit. In this research, the use of some essential oils (Cuminumcyminum, Zataria multiflora, Mentha piperita) to control blue and green molds in orange fruits was investigated. Valencia and Jiroft Local oranges were dipped in Penicillium italicum and P. digitatum suspension and were put in waxy papers sprayed with the essential oils at three levels (1, 2.5 and 5%), and thiabendazole fungicide (TBZ) 0.2%. Control fruits were put in waxy papers without any treatments. Then, all the fruits were stored at 8 oC and 85-90% relative humidity for 3 months. Essential oils of Cuminumcyminum (cumin)and Zataria multiflora (Shiraz origanum) were effective on control of blue and green molds in orange varieties at the levels of 5% and 1, 2.5 and 5%, respectively. These treatments had no significant differences with thiabendazole fungicide. The treatments containing mint essential oil had the highest level of rot by blue and green molds. The results of the sensory evaluation showed that the essential oils did not make any special taste in orange varieties. Essential oil of Shiraz origanum in different levels caused improper appearance in the skin of orange varieties and as a result, they obtained the fewer score in the sensory attributes (texture, acceptability). Therefore, for increasing the storage-life of Valencia and Jiroft Local oranges, application of waxy paper containing 5% of cumin essential oil was recommended.

In this study, inhibitory effects of herbal products (licorice root and neem leaf extracts, Aloe vera gel) on Aspergillus niger growth isolated from Mazafati palm dates and control of this mold in Mazafati palm dates were studied. The mold was isolated from rotten Mazafati palm dates. Herbal products were added to melted potato dextrose agar medium in different concentrations (0.1, 0.5 and 1% for Licorice root and neem leaf extracts and 0.25, 0.35 and 0.50% for Aloe vera gel). Plates containing the herbal products were inoculated with fungi discs (7mm diameter) and incubated at 25°C ± 1. The diameter of fungus colonies (mm) were measured daily. There was significant difference (P < 0.01) among the herbal extracts and also their concentrations in preventing Aspergillus niger growth. The results showed that inhibitory effects of licorice root extract on Aspergillus niger growth were significantly more than that of neem extract and Aloe vera gel. High concentration of the extracts had also more inhibitory effects on the mold growth. The licorice root extract at 1% concentration showed more reduction in the growth of Aspergillus niger and also was effective on control of rot in Mazafati palm dates. The licorice root extract did not make any special taste in Mazafati palm dates and obtained the more score in the sensory attributes (taste, appearance, acceptability).

In this study, the effect of water and Sodium diacetate solutions on reduction of pollutions in Mazafati  rutab was investigated. Date branches were washed at the last stage of Khalal by spraying of pure water and Sodium diacetate solution (4000 ppm). Total microbial and fungal counts were determined before washing as well as two, three and four weeks after washing of the fruits on tree. Mazafati rutab samples were packed after harvest and stored in cold room and also at ambient temperature for 6 months. The results showed that surface and microbial pollutions significantly (P<0.05) decreased after washing of the fruits with pure water and Sodium diacetate solution. Total microbial and fungal counts gradually increased during stage of fruit maturity. Rotting rate was significantly (P<0.05) high in the dates treated with Sodium diacetate at harvest time. The moisture content of the dates decreased but total soluble solids (TSS) increased during storage at ambient temperature. In all treatments, pH content decreased and percent acidity (as lactic acid) increased during storage. Total microbial counts in the dates treated with Sodium diacetate was significantly (P<0.05) lower than other treatments during storage. The results indicated that washing of Mazafati date bunches at the last stage of  Khalal by spraying of pure water can be effective in reduction of surface pollutions on the fruits. Mazafati rutab should be stored in cold rooms to prevent the activity of microorganisms and pests and increase the storage life.

In this research, the effect of acetic acid and sodium diacetate on ripening of Mazafati date fruit was studied. Date bunches were harvested at the end of khalal stage and were dipped in acetic acid (4%) and sodium diacetate (0.3%) solutions. The treated bunches were placed within a room at 38-40°C and 70-80% relative humidity for 3-5 days. Chemical (Total soluble solids, total sugar, reducing sugars, moisture content, acidity, pH) and microbial analysis and also ripeness degree were determined for the treatments. Acetic acid and sodium diacetate solutions induced ripeness and softness of Mazafati date fruits. Chemical composition (TSS, reducing sugars, total sugar) of naturally ripened fruits was more than the treated fruits. Moisture content of the treated fruits was significantly (p<0.05) more than the control, while there was no difference between them on acidity. Sensory evaluation analysis showed that acetic acid and sodium diacetate treatments reduced the fruit firmness and there was no significant difference (p<0.05) between them on taste. It was concluded that treating of Mazafati date with acetic acid solution (4%) and placing it at 38-40°C and 70-80 % relative humidity for 3-5 days was the effective and economical method for artificial ripening of the fruits.

Mazafati variety is one of the most important export products in Kerman province. Contamination with dirt, because of windy area and Transmission of fungal spores and other factors reducing the quality, are the most important problems to manufacturers. In this study, cleaning and covering of Clusters in the level of Khalaal were evaluated in four ograpHical directions to reduce pollution. Cleaning treatment was applied by pressurized air with a fan and acetic acid (0.4%). Coverings used on clusters were burlap, polyethylene fabric and 5% starch solution with nutmeg oil Hindi (4000 ppm). Effect of treatment was evaluated for a month during step conversion Khalall to Rotab Chemical tests include reducing sugars, total sugars, total soluble solids, Moisture, acidity, pH and Microbial tests including total count and counting microorganisms, mold and yeast. The results of the statistical analysis of data showed that the Brix, moisture content and pH in three types of cover compared to control were significant change (p≤0/01). Over time, the pH increased and acidity decreased in all treatments. The pH in the first week of sampling was 5.62 and in the fourth week were 6.95. During fruit ripening date, firmness also decreased significantly. Results showed that all three treatments with significant differences compared to control are superior in maintaining the properties of quantitative, qualitative and control of microorganisms and Preserved fruits on the tree. Sugar content in plots which were clean with fan was 39.8 that 36% increase compared to the control treatment but in Dates that were cleaned with vinegar 33.7% decreased. Most of PH (6.1) was observed in the polyethylene and starch covering treatments. Soluble solids in polyethylene covering treatment were 34.34. During fruit ripening, firmness also decreased significantly (p≤0/05). Cleaning and covering various treatments significantly decreases microorganisms in date compared to control. The number of microorganisms during the first three weeks of research did not significant increase but in the fourth week significantly increased which in this case also covers treatments and cleaning was superior compared to control (p≤0/01). The results obtained with nutmeg oil Hindi starch coating with polyethylene wrapping treatments than others in maintaining the properties of quantitative, qualitative and microbial recommended excels is the star turn.

Lactic acid bacteria (LAB) have an important role in agriculture and food industry. Lactic acid bacteria are characterized as Gram-positive cocci or rods, catalase negative, non-pathogenic, and non-motile bacteria. Metabolic properties of lactic acid bacteria are important for their selection as starter cultures in production of fermented products, especially bread. The aim of this study was to examine the technological properties of the sourdough Lactobacilli isolates in order to select the proper isolates for bakery industry. In this study, technological properties of 71 lactobacilli isolated from traditional sourdoughs were evaluated. The technological properties included acid production ability, proteolytic and amylolytic activities as well as exopolysaccharides production. Most of the lactobacillus isolates (91.55%) showed amylolytic activity but isolate 51 had the highest amylolytic activity. All the isolates exhibited proteolytic activity, acidifying ability, and exopolysaccharides production. The lactobacillus isolates 31, 40, 44, 47, 51, 52, 57, 64, 70, and 71 showed the highest proteolytic activity. Exopolysaccharides production was also the highest in the isolates 19, 60, 8, 34, 36, 62, 54, 48, 68, 13, 52 and 12. The lactobacillus isolate 14 was reported the best isolate in the case of acidifying ability. Some of the lactobacillus isolates had the proper technological properties for using in bakery industry. Therefore, they could be used as starter cultures in bread production after studying in baking tests.

Bioactive compounds such as polyphenols and fibers in plant products are recognized for their health benefits. In this study, antioxidant activity, polyphenol contents, pigments, and total crude fiber of date pit of Mazafati and Kalutah varieties (Kerman, Iran) were investigated. Total crude fiber, phenolic compounds, and pigments were then determined using fiber tester and spectrophotometric method, respectively. The antioxidant activity was also determined by the scavenging of DPPH (2, 2-Diphenyl-1-picryl-hydrazyl) free radical. Date pits of Mazafati and Kalutah had light to dark brown colour. Total phenolic content of Bam Mazafati, Jiroft Mazafati, and Kalutah varieties were 1898.27, 1840.93, and 1952.93 mg gallic acid equivalent/ 100 g, respectively. The antioxidant activity of pit extracts ranged from 194488.6 to 248166.7 mMol Ascorbic acid/ 100 g. The date pits, on the average, contained 11.72 μg/ ml carotenoids, 4.14 μg/ ml chlorophyll a, and 5.85 μg/ ml chlorophyll b. The total crude fiber was also in the range of 26.18-28.56%. The present study indicated that the date pits of Mazafati and Kalutah varieties had high antioxidant activity and also were a good source of fiber and phenolic compounds. Therefore, date pit can be used in different food formulations and also its extract as an antioxidant in preventing food oxidation is recommendable.

In this study, the inhibitory effect of 71 Lactobacilli isolated from traditional sourdoughs against Bacillus cereus was evaluated and compared by using three methods (spot on lawn, well diffusion and disk diffusion). There was no inhibition zone around the discs and wells in the well diffusion and disk diffusion methods. The inhibitory effect of Lactobacillus isolates against Bacillus cereus in the Spot on lawn method was observed as a clear zone around the colonies. All Lactobacillus isolates were able to inhibit the growth of Bacillus cereus in the spot on lawn method, but there was a significant difference (p

The study of biochemical characteristics and metabolic activity of Lactobacilli is necessary for selecting strains to be used as starter cultures for bread production. In this study، biochemical characteristics، acidification and probiotic properties of Lactobacillus strains (Lactobacillus plantarum، L. curvatus، L. paralimentarius) isolated from traditional sourdoughs were evaluated. All three Lactobacillus strains showed growth at 15ºC and different levels of NaCl (2، 4، 6. 5%) and pH (4. 4، 9. 6). Lactobacillus plantarum was capable of growing at 45°C. The Lactobacillus strains had capacity to ferment a large spectrum of carbohydrates. Lactobacillus plantarum and Lactobacillus curvatus was able to ferment pentoses (xylose and arabinose). Lactobacillus curvatus and Lactobacillus paralimentarius did not ferment rhamnose. The lactobacillus strains showed a proper acidifying ability after 9 h of incubation at 30°C، with pH values between 4. 5 and 4. 9. The results showed that Lactobacillus plantarum and Lactobacillus paralimentarius have potential probiotic value according to acid and bile tolerance tests.

Spoilage of bakery products is mainly caused by molds. Nowadays، consumers demand for minimal use of chemical preservatives in foods. Thus، researchers attempted to use lactic acid bacteria as biopreservatives in food. Lactic acid bacteria produce a number of antifungal metabolites، e. g. organic acids، diacetyl، acetone، hydrogen peroxide، antifungal peptides and bacteriocin، by which the shelf-life of food is prolonged. In this study antifungal properties of lactic acid bacteria including L. plantarum and L. reuteri in sourdough in inhibition of Aspergillus niger and two Aspergillus species (yellow and black molds) isolated from bread was investigated. Results showed THAT after 2nd day، Aspergillus niger growth was significantly (P<0. 05) higher in control culture than that of sourdough supernatants cultures. In case of yellow and black molds، sourdough supernatant cultures did not retard mold growth.

The effect of the addition of freeze-dried sourdough containing Lactobacillus plantarum ATCC 1058 and Lactobacillus reuteri ATCC 1655 on loaf physical and sensory characteristics as well as the shelf life of bread was investigated. Freeze-dried sourdough caused a decrease in pH and an increase in total titrable acidity of dough and the resulting bread. However, the physical properties of the bread (volume, height) were not changed. The moisture content of the control bread was significantly higher than that of sourdough added samples. The least moisture content (25.66%) was reported in freeze-dried sourdough bread containing Lactobacillus reuteri. Sensory characteristics of all breads were negatively influenced during bread storage. Maximum sensory was obtained for control bread followed by sourdough bread containing Lactobacillus reuteri. The addition of dried sourdough increased the shelf life of the bread. The starter Lactobacillus reuteri inhibited mold growth and extended the shelf life of the bread to 10 days compared to that of control bread (4 days).

The effect of fresh and freeze-dried sourdoughs containing Lactobacillus plantarum and Lactobacillus reuteri on sensory characteristics and crumb firmness of pan bread was studied. The freeze drying process significantly decreased the number of lactobacilli in the sourdough. Nevertheless, Lactobacillus reuteri showed more resistance to the drying process than Lactobacillus plantarum. Breads with higher loaf volumes and less moisture content were obtained when freeze-dried sourdough containing Lactobacillus reuteri was used. Crumb firmness increased upon storage for all the treatments. Both fresh and freeze-dried sourdough containing Lactobacillus reuteri produced bread with the least crumb firmness during storage. Sensory scores (after 72 h storage) for breads prepared from freeze-dried sourdoughs containing Lactobacillus reuteri were higher than those of other treatments. In conclusion, Lactobacillus reuteri can be regarded as suitable starter culture for production of dried sourdough.

Dehydration of Mazafati Rutab is a method to prevent its spoilage. Dehydration is necessary for Mazafati Rutab because it contains too much moisture. If the moisture content of Mazafati Rutab is decreased properly, it need not be stored under refrigeration. The present study was carried out in an attempt to decrease the moisture content in order to increase the shelf life of Mazafati dates. Samples were dehydrated in a drying room at different drying times and 50-55 oC. The moisture content and quality characteristics of Mazafati dates such as acidity and sensory evaluation (texture, flavour and overall acceptability) were determined at 3-hour intervals and also drying curve of the fruit was drawn. Relative humidity in the drying room was 10-15%. During the drying process, the acidity content gradually increased due to the activity of microorganisms but organoleptic properties decreased especially affer 12 hours of drying time and at moisture levels less than 22%. Finally, drying time of 9-12 hours and acceptable moisture content of 22% were recommended. Dates with over 22% moisture levels are an easy target for microbial attack but the desirable quality of the fruit decreases at moisture levels below 22%.