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

The date palm (Phoenix dactylifera L.) plays an important social, environmental, and economical role for many people living in arid and semiarid regions of the world. Date fruit is one of the major agricultural crops in the East Asia region, where about 90% of the world's dates are cultivated. Dates are rich in certain nutrients and provide a good source of rapid energy, due to their high carbohydrate content (70–80%). Moreover, date fruits contain fat (0.20–0.50%), protein (2.30–5.60%), dietary fibre (6.40–11.50%), minerals (0.10–916 mg/100 g dry weight), and vitamins (C, B1, B2, B3, and A) with very little or no starch. In addition to the direct consumption of the fruit, various industrial products are also extracted derived from this product, including date juice, date honey, liquid sugar, vinegar, alcohol, caramel, date paste and date chocolate. The annual production of one million and 400 thousand tons of dates in Iran has made Iran the second pole of date production in the world after Egypt. Zarin Dasht region is located in Fars province, and the annual production of dates in this region reaches more than 1000 tons. The aim of the present work was to investigate the chemical composition, carbohydrate, and antioxidant capacity of two cultivars of Zarin Dasht dates.
 
After collection, all date fruits were washed with tap water, and the seeds were then removed, and the flesh were shade dried at room temperature. The dimensions and area of the imaged surfaces were measured by the physical properties measurement device in 100 repetitions. The working principle of this device is based on image processing technique. By placing the product in three different positions and perpendicular to each other, pictures of the date samples were taken individually. Date mass was obtained using a sensitive digital scale with an accuracy of 0.01 g. The displaced water method was used to determine the volume and density of each date seed. Bulk density, date porosity, geometric mean diameter, sphericity coefficient and surface area of the samples were determined. The amount of moisture was determined by weight method, ash by burning in an electric furnace, titratable acidity based on malic acid and pH of the samples were measured by a digital pH meter. To measure the amount of total phenol in the fruit, Folin–Ciocalteu reagent was used and the absorbance of the reaction mixture was read at 750 nm by a spectrophotometer. The amount of total phenol was reported in terms of gallic acid. The antioxidant capacity was determined through the neutralization of free radical 2 and 2 diphenyl 1-picrylhydrazyl (DPPH). To measure the sugar of all samples, first a standard curve was drawn from the glucose solution in different concentrations, then the sugar content of the samples was measured in milligrams per gram of fresh weight at 490 nm using the sulfuric phenol method. The amount of crude fibre was calculated according to the standard method of AOAC-991/43. The amount of fat was obtained with the Universal Extractor E-800 device for 3 hours at a suitable temperature and in 250 cc of n-hexane solvent. Finally, the statistical analysis of the data was done factorially and in the form of a completely random design in 3 replications using SAS 4, 9 software and the comparison of the means was done using the LSD test at a probability level of 1%.
 
According to the results of this research, there was a significant difference in all qualitative traits except pH (P<0.01). In comparing the characteristics of the palms of two cultivars, it was observed that the highest amount of fibre (1.78 %), titratable acid (0.59 %), ash (1.64 %) and fat (0.85 %) is related to Shahani cultivar,and the highest amount of total phenol (8.1 mg/gFW), DPPH inhibitory property (13 %), moisture (18.7%), sugar (63.8 %), protein (0.29 %) and pH (5.74) belonged to Khassui cultivar. Also, comparing the kernel characteristics of two cultivars, it was observed that the highest amount of ash (3.17 %), total phenol (10.8 mg/gFW), antioxidant property (72 % DPPH inhibition), protein (2.55 %), pH (6.11) and fat (9.20 %) related to the kernel of Shahani variety and the highest amount of fibre (26.2 %), moisture (5.26 %), sugar (15.8 %) and titratable acid (0.38 %) belonged to the kernel of Khassui cultivar. Overall, the kernel of Shahani variety had more DPPH inhibitory power among all the samples.

The purpose of this study is to investigate the chemical and microbial properties of date syrup during different stages of production line from the raw material to the final product. The amounts of total soluble solids, pH, acidity, total and reducing sugars, polyphenolic compounds, antioxidant activity and microbial count were measured and the type of microorganisms was determined based on phenotypic characteristics in different stages of production. The obtained results showed that during the stages of juice clarification and concentration, pH gradually decreased and acidity, total sugar, reducing sugar and total solid matter increased and reached their maximum in the syrup. Comparison of traditional syrup with factory produced syrup showed more pH and acidity, total and reducing sugar, total soluble solid, polyphenolic compounds and lower antioxidant activity for traditional syrup compared to the produced one. In general, the content of polyphenolic compounds and antioxidant activity gradually decreased in different stages of production, so that date syrup (279 mg of gallic acid per 100 grams of sample and 33%) indicated higher content of polyphenolic compounds and antioxidant activity than dates (388 mg of gallic acid per 100 g of sample and 57%). The results of the microbial test showed the lowest microbial load for the produced syrup compared to dates and different syrups. However, the presence of B. licheniformis in the syrup makes the product sour, in this regard finding a suitable solution to increase the shelf life of the product seems necessary. The traditional syrup showed a lower microbial load than the produced syrup, although B. licheniformis was observed in the traditional syrup despite the high heat treatment. Based on the obtained results, the date syrup was free of coliforms, which indicates maintaining the hygienic principles of manufacture during the production line.

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.

Discovering new strains with useful industrial and pharmaceutical capabilities and avoiding the import of microbial strains from three economic perspectives, passive defense and conservation of the countrychr('39')s microbial genetic resources are of great importance. The presence and activity of appropriate microbes is an essential factor in the success of fermentation processes. Fermented foods and beverages are among the most important and best natural sources for discovering useful strains. In this study, samples of traditional date vinegar were obtained from Kerman market and their physicochemical (pH, acidity, total soluble solid, total phenolic compounds, and antioxidant activity) and rheological properties (consistency coefficient and flow behavior index) were investigated, also their microbial population were assessed by molecular methods (ARDRA and 16S rRNA gene sequencing) for the presence of acetic acid bacteria. The result of this study was to identify two species of acetic acid bacteria, namely Acetobacter pasteurianus and Komagataeibacter europaeus. In addition, Lactobacillus sp., Paenibacillus sp. and Staphylococcus epidermidis were detected in vinegar samples. On the other hand, vinegar sample were different in terms of microbial load and the type of available microbes. Date cultivar, production method and vinegar age are the possible causes of this variations. Finally, the application of acetic acid bacteria identified in this study as starter culture for fruit vinegar production is suggested. These bacteria were stored with FCC-10971 and FCC-10973 codes in the Food Culture Collection of Shahid Bahonar University of Kerman and can be ordered by other researchers.

Nowadays due to the interest of, asking for increased food production and the food industry focus on redesigning   to optimize functional as well as maintain or improve the taste and nutritional value of the product.Palm kernel due to its significant amount of compounds can be used in beneficial food production as a cheap and functional source. In this study the nutritional benefits of palm kernel meal in 3 different levels (5, 10, 15%) was added to the formula Piccoli pasta and laboratory chemical, physical, and sensory quality was conducted for three times. Palm kernel powder-free pasta also was used as a reference sample. Then amount of this features were investigated in the final product. In addition, colorimetric tests, tissue analysis of raw and cooked samples, phenolic compounds measurement and sensory evaluation of taste, color and texture</span> of the product was done. Data analysis shows that by increasing the amount of palm kernel flour, protein and moisture decreased, but fat, ash and fiber increased. In addition cooking analysis shows that Palm kernel meal volume loss increased while the cooking time is decreased comparing to traditional product.In the sensory evaluation there was no major difference and all three were in a same acceptable level. The results show that phenolic compounds increased with increasing palm kernel flour percentage. tissue analysis does not show any particular trend in the sample. According to the results replacement of ten percent of flour with palm kernel flour has the best result of checked ones.

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).

Studying the microbiota of food materials is important from sanitary, spoilage and technological perspectives. Due to manual harvesting, grading and packaging of date fruit (Phoenix dactylifera L.), it's not surprising to find bacteria of human origin in date fruit products. On the other hand, microbes present in date palm, especially high moisture content fruits, could produce lactic acid and acetic acid and make the fruit sour, so this kind of microbes potentially could be useful especially in food fermentation and vinegar production. In this project, seven varieties of date fruits were examined chemically and microbiologically. Total solid and acidity of dates were between 72% to 86% and 0.06% to 0.78% respectively. Isolated bacteria were identified by 16S rDNA amplification and restriction analysis (ARDRA), sequencing and 16S rRNA gene comparison. The results show Staphylococcus epidermidis, Aerococcus, Bacillus and Leuconostoc mesenteroides are the present bacteria in local date fruits.

  Date palm fruit (Phoenix dactylifera L.) is an important agricultural product of Iran. This fruit is a good source of energy and is rich in nutrients. Amongst several important varieties of dates, Mazafati in terms of marketability and consumption in Iran is placed in first rank. Because of unsuitable storage conditions and packaging types during storage period, fruit quality changes and so the product turns sticky and hard due to syrup exudation and moisture loss. To overcome this problem the application of edible coating is proper assistance. Edible coatings have been widely studied in the last years because of evidence about their beneficial effects on fruits and vegetables. Modification of fruits tissue metabolism by affecting respiration rate, extension of storage life, firmness retention, transportation of antimicrobials, antioxidants, and other preservatives and microbial growth control are the main functional advantages attributed to the use of edible films and coatings. There are different kinds of films and coats which are used such as polysaccharide, protein, lipid and composites. Lipid films have good water vapor barrier properties, due to their low polarity. Also temperature is one of the most important factors, which affect the shelf life and the quality of date fruits. The purpose of this research was to study the effect of lipid based edible coating (glycerylmonoestearate and carnauba wax) and storage temperature on quality of Mzafati date fruit. In this research Mazafati date fruit coated with lipid based coatings (glycerylmonoestearate and carnauba wax) and stored at 4 and 25 C° for 3 months. During this period of storage weight loss, hardness, titratable acidity, total soluble solids (brix), reducing sugars, color (lightness, redness and yellowness) and sensory properties (color, texture, flavor and total acceptance) of date palm fruit were evaluated. The experiments were factorial with a completely randomized design. The edible coating, temperature and storage time were the independent variables. Analysis of variance (ANOVA) was conducted for data using SPSS 21 software. Differences among the mean values were also determined using Tukey test. A significant level was defined as a probability of 0.05. Result showed that the coatings were effective to decrease the weight loss and rate changing titrable acidity and color and protecting sensory properties of the date palm. The coated date fruits had more titratable acidity than the control. Although difference of hardness, titrable acidity, total soluble solids and reducing sugars of the coated date palms not significant but carnauba wax coat was more effective to protect color and sensory properties. Edible coating caused increasing lightness, yellowness and sensory scores of date palm significantly. Increasing of storage temperature increased weight loss and decreased yellowness significantly. Increasing of storage time also caused increasing hardness, redness and decreasing lightness and sensory scores. At the end of storage time least value of weight loss and most value of yellowness (8.13% and -0.841 respectively) were related to 4 C° and glycerylmonoestearate coat also most value of lightness and total acceptance score and least value of redness (17.2, 3.1 and 3.99 respectively) were related to carnauba wax coat. The use of lipid based edible coating and low temperature storage could delay changes in physicochemical and sensory properties of date fruit and increase the shelf life of Mazafati date fruit

The date palm (Phoenix dactylifera L.) plays an important social, environmental, and economic role for many people living in arid and semiarid regions of the world. Fruits of the date palm are very commonly consumed in many parts of the world and considered as a vital component of the diet and a staple food in most Arab countries. Nearly 2000 cultivars of date palm are known in the world, but only some have been evaluated for their performance and fruit quality. Dates are rich in certain nutrients and provide a good source of rapid energy, due to their high carbohydrate content (70–80%). Moreover, date fruits contain fat (0.20–0.50%), protein (2.30–5.60%), dietary fiber (6.40–11.50%), minerals (0.10–916 mg/100 g dry weight), and vitamins (C, B1, B2, B3, and A) with very little or no starch. The aim of the present work was to investigate the chemical composition, carbohydrate, and antioxidant capacity of two date palm varieties grown in Hormozgan and Farce province.
After collection, all date samples were washed with tap water, and the seeds were removed, dried at room temperature under shadow. Moisture content was determined by drying samples in oven at 60 °C until constant weight was attained. The determination of proteins was done by Bradford method. Color measurement of fruit made using a portable CR-400 colorimeter (Minolta Chroma Meter CR-400 Osaka japan).Total polyphenols were determined as described by Waterhouse, 2002.The results were expressed as milligram gallic acid equivalents per 100 g of dry weight (mg GAE/100 g DW). Total flavonoids content (TFC) of the date extracts were measured according to the colorimetric assay of Chang et al., 2002. The hydrogen peroxide (H2O2) scavenging ability of palm dates was carried out using 2, 2-diphenyl- 1-picryl hydrazyl (DPPH) spectrophotometric method described by Choi with some modification.
Based on the results, The highest fruit length (43.6 mm), weight of pulp (9.3 g) and antioxidant activity (57 mgFW) were found in Piarom date of Hajiabad and the highest phenol (20.7 mg/gFW), TSS (77.3%) and titratable acid (0.023%) were recognized in Zahedi date of Hajiabad. Although date varieties from Jahrom showed better color index and tannin content than Hajiabad date. In comparison between two varieties, Piarom date was better in fruit weight (28.3 g), moisture content and protein content (7%) and flavonoids (22.2 mg CEQ/gFW) than the Zahedi date. However, the carbohydrate of Zahedi date (85%) was higher than the Piarom date. Therefore, in addition to the variety, location and climate condition also have the important role in determining the nutritional value of date palm fruit.

Mazafati date is one of the most famous and delicious date varieties which has been classified as soft dates. It has a dark red and Soft tissue. This date is third economic variety of our country after Saamaran and Shahani. Regarding to the importance of acidity level the changes of acidity level during storage was predicted by neural network . In doing so , ozone gas , the edible coating of chitosan and different temperatures (5,15,25 oC) were used as strategies to increase durability of Mazafati date during 60 days,
and dates acidity was measured every 3 days . Ozone , chitosan coating and different temperatures were used as in put of network. The results showed that newff artificial network with topology of 1-17-4 , the correlation coefficient of 0.99 and error square mean of 0.0013 by applying hyperbolic sigmoid tangent function and learning pattern of levenberg marquardt is considered as the best neural model in predicting the changes of acidity level. Generally , it can be said that artificial neural network is a reliable method to model and predict the changes of date acidity and similar products .

Because of unsuitable storage conditions and packaging types during storage period, change physicochemical characteristics of date palm fruit and so the product turns to sour, sticky and hard. The application of edible coating to overcome this problem has been suggested. Edible coatings may enhance the boundary layer resistance resulting enhanced shelf life of product. The purpose of this research was evaluating effect of polysaccharide based edible coating on quality of Mazafati date fruit. In this research Mazafati date fruit coated with polysaccharide based coatings (starch and pectin) and stored at 4 and 25°C for 3 months. During this period of storage total soluble solids (brix), PH, titratable acidity, Water insoluble solids, weight loss, percent of pestilence and reducing sugars were evaluated. Results showed that coating, temperature and storage time effect on most physicochemical properties of date fruit significantly. Coating delayed some changes of the physicochemical properties of date fruit. Pectin was more effective than starch on stability of date fruit. Increasing temperature decreased pH and Water insoluble solids and increased brix, titratable acidity, weight loss and reducing sugars. Least value of weight loss (5/12%) and most value of Water insoluble solids (14%) were related to pectin coating and 4°C and most value of titratable acidity (0/29%) was related to pectin coating and 25°C at the end of storage time.

In this research, the treatment of ozone gas and chitosan edible coating in different treatments were used during palm date storage in order to evaluate the palm date shelf life and decrease it's microbial load. In doing so, the studied dates were treated by ozone in three levels(0,2.5,5ppm) for 1 hours, then they were coated by chitosan in three levels (1,2%) in the form of response surface design .afterwards the packaging was performed by available commercial methods and until the end of experiment, they were kept in three temperatures (5,15,25oc).the results of growth of yeast, molds and coliform and total number of bacteria showed that their number is inversely related to increasing the concentration of ozone gas and used chitosan percentage and it is directly related to temperature and storage time with due attention to economic problems, there is tendency to use less concentrations of ozone gas and chitosan edible coating and also palm date storage in room temperature for long periods and based on this ,the data were optimized and the values of ozone, chitosan, temperature and time were suggested for 29% humidity date in order 2.01ppm,0.84%,22.4oc, and 33.99 days .

Nowadays, the investigations on sugar replacement with other sweeteners increased because of the relation of sugar consumption with some diseases such as blood pressure, dental decay, obesity and increment of the glucose and insulin which especially is dangerous in diabetic patients. In this study, sugar was replaced in 5 levels (0, 25, 50, 75 & 100%) with date puree in dunat formulation and physicochemical and sensory properties and shelf life of final product were assessed. Results showed that moisture and water activity values increased with more replacement of dunat was decreased in 75% replacement level. The oil uptake percent and special volume decreased from 50% and 75% replacement levels, respectively. Although L٭ and b٭ values of the dunat crust was decreased in 50% and higher replacement levels in compared with control sample, a٭ value was increased in 25% and higher replacement levels. While the a٭ value of the dunat crumb increased in 25% and higher replacement levels, L٭ and b٭ values decreased from 25% and 50% replacement levels, respectively. Results from panelist’s assessment also hadn’t significant difference with control sample up to 50% replacement level. Results from this study showed that 50% replacement of sugar with date puree in dunat formulation not only keep appropriate sensorial properties of products, but also reduce oil uptake in a significance difference in compared to control sample and in special volume and porosity, treated samples haven’t significance difference with control sample. Also increment in replacement level up to 50% of date puree, whilst increase moisture and decrease hardness of products in each three period times and regard to water activity value, lead to increase in dunat maintenances time.

“Date Arde” is energetic new product that traditional was produced in countryside area of the mount zagros in Iran. This product formed from mixed arde (roasted، decorated and milled sesame seed) with dates paste in portion (25%w/w). The average oil of “Date Arde” is around 9-10%. This study was carried out for investigation the effects of flavor compounds (cumin، cinnamon، ginger) and coatings (chocolate، gelatin، roasted flour with confectionary fat) on the physical (Color، texture)، microbial (Total count، yeast mold) and organoleptic (Softness، flavor، color and over all acceptance) characteristic of “Date Arde” that include berhi dates variety. Analysis of data showed that maximum levels of flavoring for good acceptance was 1% (w/w) of dates، also this level (1%) influenced significantly (p≤0. 05) on texture of product. On the other hand، cumin flavor was accepted with the highest degree. Analysis of findings showed that coating of “Date Arde” flavoring with cumin affected significantly (p≤0. 05) the texture، color and total acceptance. So that chocolate coating showed the best acceptance.

One of the most important problems in date processing is unsuitable storage conditions, packaging types and then changing physicochemical characteristics.In this research date fruits (Kabkab variety) were packed within aerobic atmosphere and vacuumed PA/PE pouches and stored at different temperatures (-20, 4, 25 and 40 ºC). The samples were evaluated for textural parameters (hardness, adhesiveness, cohesiveness and springiness) monthly during the storage period up to 6 months. The storage temperature, time and packaging type greatly (P < 0.01) affected hardness, cohesiveness and springiness tested in date fruits during storage.Time and packaging type had significant effects on date adhesiveness, while temperature did not affect it. All texture properties were higher in the dates stored at 40 ºC within all packaging types in sixth month. An increase of hardness was detected for atmospheric and vacuum- packed datesthroughout the storage period. However, it was noted that increasing was significantly greater at 40 ºC compared to other storage temperatures.

Baker's yeast is one of the most important additives for improving the bread quality and molasses is a commonly used source of sugars for producing baker's yeast. Nowadays, due to increasing the fermentation industries and limitation in suitable sources of sugars, the use of other carbohydrate sources may be considered.In this study, the possibility of baker's yeast production in three cultures of date, raisin, enzymatic hydrolyzed whey and molasses as a control was investigated.Also, the total amount of biomass, consumption of sugar, strength of levy and kinetic's parameters of growth in all mediums were determined.For enriching the mediums, yeast extract and pepton were used in order of 3.5 and 7%, respectively. Fermentation process carried out during 12 houres and the temperature is maintained constant to 30 C°. Agitation was of 150 turns per minutes and ventilation fixed at 2 V.V.M. According to the results,maximum and minimum amount of biomass were 93.33 and 81.35 g/l that they related to date and whey, respectively.The consumption of sugar except whey which had the lowest level, in other cultures had no significant difference.The highest yield (0.35g/g) is observed in date but the lowest yield was 0.32 g/g in whey. Also, the baker's yeast which growed in raisin extract, had the highest value in strength of levy.

Date fruit is rich in carbohydrates، dietary fibers، vitamins and essential minerals. In present study، date sugar was used as an alternative for sucrose in sour cherry jam because of its nutritional properties. The physic-chemical and sensory characteristics of the product was assessed and compared with the control sample. At First، both dietary and the control samples were prepared under atmospheric pressure. The samples were assessed for the physic-chemical parameters including acidity، pH، Brix and insoluble solids content. Sensory evaluation was performed by presenting the questionnaires. The final values of viscosity and Brix values for the control were 8733 centi poase and 70، and for dietary jam were 7233 centi poase and 54، respectively. The pH range for both samples was found between 3-3. 8. There were no significant deference between dietary jam and the control samples in view of acidity an insoluble material. Both products showed good acceptability among panelists. The results indicated that there were no significant differences between dietary jam and the control in view of overall acceptability. It could be concluded that the application of date sugar as an alternative for sucrose in manufacturing of dietary jam had no deleterious effect on the sensory characteristics of the product (i. e. taste) and could receive good acceptability among consumers.

In this study، Mazafati date samples were dried using a cabinet drier at five temperatures (50، 60، 70، 80 and 90 ˚C) and air flow rate of 1 m/s. Changes of total soluble solids، browning، pH، acidity and color parameters (L*، a* and b*) of date samples during drying were determined and compared. The results showed that total soluble solids، browning index and acidity increased and pH of date samples decreased. Moreover، L* and b* color parameters decreased and a* value increased. Overall، it was concluded that the moisture of Mazafati dates can be reduced by industrial drying. Furthermore، air temperatures of greater than 70˚C have negative effects on color of the date samples. Therefore، drying temperature of 70˚C was found to be the optimum condition for drying process of Mazafati date.