Study of Chemical and Microbiological Properties of Saffron Dehydrated by using Solar Drying System (original) (raw)
Related papers
Journal of Agricultural Science and Technology, 2014
In the present study, saffron was dried using a heat pump-assisted hybrid photovoltaicthermal solar dryer. The effect of different drying air temperatures at three levels (40, 50, and 60 o C) and two different modes of the dryer (with and without heat pump system) were investigated on drying behaviour of saffron. After collecting the pertinent data, eleven drying models were used to describe drying characteristics of saffron. Quality characteristics of the dried products (including: colouring, aromatic strength and bitterness) were also evaluated. The results indicated that drying time decreased by 62% with increasing air temperature from 40 to 60 o C. Moreover, applying heat pump with the dryer reduced RH of drying air and, consequently, enhanced drying rate and shortened drying period by 40%. A two-term drying model presented a relatively higher R 2 and lower 2 χ , MBE, and RMSE values at both modes of drying and, therefore, was selected to explain drying behaviour of saffron among the other models. The results of saffron quality evaluation showed that colouring characteristics of saffron improved with drying temperature and heat pump system. Meanwhile, aromatic strength of saffron increased with increasing air temperature. But, no significant change in bitterness was observed at different levels of temperature and heat pump system.
2015
Saffron is known from ancient times, and not only as a spice used in food but as dyeing, beauty product and especially for its pharmacological properties. Actually, its main use is in food as,it is one of the few spices that is capable of transmitting color, aroma, and flavor. Commercial saffron enterprises demand aroma evaluation more and more insistently through simple and reproducible techniques. Consumer knowledge of the spice has improved and they begin to demand saffron that possesses quality in a much wider sense. This study reports the effects of drying methods (Shade-drying and microwave drying) on Safranal content of saffron (Crocus sativus L.) and simultaneous method validation is presented by Several parameters: RSD, LOD, LOQ, Spike amount, % Recovery.. Samples of saffron were analysed by High Performance liquid chromatography. Result suggested that microwave drying retain maximum concentration of safranal (0.072± 0.003 mg/100mg of stigma) as compared with sample dried u...
Effect of Drying Temperature on Colour Parameters and Secondary Metabolites Content in Saffron
Introduction Drying of stigma is the most important post-harvest process in saffron production. Traditionally, the stigma is dried at ambient temperature which increases the drying time and also increases the probability of contamination of the product. Recently, other dehydration methods such as microwave and electrical oven are used to dry the stigma [1]. However, the usefulness of these methods should be tested on stigma qualitative parameters. Materials and Methods This experiment was performed on different drying methods of saffron stigma and corolla: 1- in the shade condition with room temperature (~ 25 °C) as traditional method, 2- in the oven at 55 °C and 3- in the oven at 75 °C. Flowers were collected from the saffron field of Saffron Research Group, University of Birjand, in autumn, 2017. After separating and drying the stigma, the color indices and the main ingredients in them (crocin and safranal) were determined in laboratory. Colour of dried stigma was evaluated using a colorimeter and the results were expressed as Hunter color values (L*, a* and b*). L is the brightness ranging from 0 (black) to 100 (white). The value b* is the yellowness ranging from negative values for blue and positive values for yellow [2]. Colour intensity (chroma) and hue angle also were calculated using related equations [2] and crocin and safranal were measured based on national standard No. 259-2. In addition, the content of anthocyanin in dried corolla was determined. Results and Discussion Effect of drying method was significant on almost all measured indices in stigma.Totally, similar to some other research [1] stigma drying in oven with temperature of 55 °C was the best treatment in terms of all qualitative parameters. Fig 1. .... References [1] Behdani, M.A.; Fallahi, H.R. Univeristy of Birjand Press: Birjand, 2015; pp. 20-122. [2] Fallahi, H.R.; Ghorbany, M.; Aghhavani-Shajari, M.; Samadzadeh, A.R.; Khayyat, M.; Maraki, Z.; Asadian, A.H. J. Environ. Str. Crop Sci. 2017, 10(4), 571-582.
Effect of drying temperature, airflow rate and flower types on dried saffron flower quality
The separation of saffron stigma from fresh flowers is the most important and the most difficult step of saffron harvesting. The separation of saffron stigma is done by hand which is time-consuming and costly. The saffron flowers will decay if separating of saffron stigma is not done quickly. Drying is one method of keeping saffron flowers. The dried saffron flowers have the higher shelf life, and deadline of stigma separating is extended. The main object of this study was to determine the best saffron flower drying method. Therefore, the effect of variables including drying temperature in three levels (40°C, 50°C and 60°C), air velocity in two levels (0.5 and 1 m/s) and three levels of flowers (buds, semi opened and fully opened) were investigated on the amount of crocin (stigma color), saffronal (fragrance) and picrocrocin (bitter taste). The results showed that the amount of crocin decreased and the amount of saffronal increased with increasing of drying temperature. The best conditions for flowers drying were obtained at 50°C drying temperature and 0.5 m/s air velocity. The dried saffron flower buds had the higher amount of saffronal than dried flowers of semi opened and fully opened.
Effect of drying temperature, air velocity and flower types on dried saffron flower quality
Abstract: The separation of saffron stigma from fresh flowers is the most important and the most difficult step of saffron harvesting. The separation of saffron stigma is done by hand which is time-consuming and costly. The saffron flowers will decay if separating of saffron stigma is not done quickly. Drying is one method of keeping saffron flowers. The dried saffron flowers have the higher shelf life, and deadline of stigma separating is extended. The main object of this study was to determine the best saffron flower drying method. Therefore, the effect of variables including drying temperature in three levels (40°C, 50°C and 60°C), air velocity in two levels (0.5 and 1 m/s) and three levels of flowers (buds, semi opened and fully opened) were investigated on the amount of crocin (stigma color), saffronal (fragrance) and picrocrocin (bitter taste). The results showed that the amount of crocin decreased and the amount of saffronal increased with increasing of drying temperature. The best conditions for flowers drying were obtained at 50°C drying temperature and 0.5 m/s air velocity. The dried saffron flower buds had the higher amount of saffronal than dried flowers of semi opened and fully opened.
Effects of mild temperature conditions during dehydration procedures on saffron quality parameters
Journal of the Science of Food and Agriculture, 2010
The dehydration procedure is responsible for saffron sensorial properties: colour, taste and aroma. Changes in the compounds responsible for these characteristics have been studied when dehydration processes at high and low temperature are employed. However, the evolution of these changes at mild temperatures is not available in the current bibliography. In this paper the effect of different mild conditions (18-20 degrees C for 24 h, 40-50 degrees C for 75 min and 55 degrees C for 75 min) applied to 45 saffron samples with the same origin was investigated. Crocetin esters, the compounds responsible for saffron colour, increased their content with no significant differences from other processes when high temperatures (55 degrees C) were used, thus producing a noticeable increment in saffron colouring capability. Similar behaviour was obtained for picrocrocin, the compound responsible for saffron taste, with higher average content at the highest temperature (55 degrees C) but without significant differences with the inferior conditions (40-50 degrees C). However, more volatile compounds were generated, especially safranal,at higher temperatures, e.g. 55 degrees C, during the dehydration procedure. The results found support the idea for employing mild to high temperatures during the dehydration process of saffron.
Molecules
Saffron is derived from the stigmas of the flower Crocus sativus L. The drying process is the most important post-harvest step for converting C. sativus stigmas into saffron. The aim of this review is to evaluate saffron’s post-harvest conditions in the development of volatile compounds and its aroma descriptors. It describes saffron’s compound generation by enzymatic pathways and degradation reactions. Saffron quality is described by their metabolite’s solubility and the determination of picrocrocin, crocins, and safranal. The drying process induce various modifications in terms of color, flavor and aroma, which take place in the spice. It affects the aromatic species chemical profile. In the food industry, saffron is employed for its sensory attributes, such as coloring, related mainly to crocins (mono-glycosyl esters or di-glycosyl polyene).
Scientific Research Communications, 2022
Saffron, the stigmasof the plant Crocus sativusL.,hasattracted the worldwide interest for its specific organoleptic and pharmacological characteristics. Cultivation of saffron in Afghanistan began in recentyears and in very short time Afghan saffron hit higher record. Till now,there is no scientific study which has analyzed its characteristicsaccording to ISO methods. In this study, the maincomponentsof Afghan saffron have been described, and quality parameters along with its characteristics were analyzed accordingto ISO-3632-2test methods. The results of moisture analysis (5.12 to 5.74%)and determination of crocin (230.52-255.15) of Afghan saffron were at the range of standard as described for category I of saffron in ISO 3632-2 test methods. However, the results of some samples for safranal and picrocrocin (38.52-40.21 for safranal and 68.86-72.63 for picrocrocin) were higher than the range of category I of ISO 3632-2.
Influence of Different Drying and Aging Conditions on Saffron Constituents
Journal of Agricultural and Food Chemistry, 2005
A dehydration postharvesting treatment is necessary to convert Crocus sativus L. stigmas into saffron spice. Three different dehydration treatments were evaluated: dehydration at room temperature; dehydration with hot air at different temperatures (70, 90, and 110°C); and dehydration following traditional processing in Castille-La Mancha (Spain) with three different heating sources (vineshoot charcoal, gas cooker, and electric coil). The time (between 28 and 55 min) and mean temperature (between 54 and 83°C) conditions for traditional dehydration were established for the first time. The highest coloring strength was obtained when saffron was submitted to higher temperatures and lower times. These findings may be supported by the fact that samples dehydrated at high temperature were more porous than those dehydrated at room temperature, as was observed by scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The higher the temperature during the process, the higher the proportion of trans-crocetin di-(-D-gentibiosyl) ester, although transcrocetin (-D-glucosyl)-(-D-gentibiosyl) and trans-crocetin di-(-D-glucosyl) ester decrease while ciscrocins did not change significantly. A thermal aging process reveals that the trans-crocetin di-(-Dgentibiosyl) ester increases when saffron is resubmitted to a heating treatment before it is decomposed by the extreme conditions. The picrocrocin extinction during the aging process does not imply a consistent generation of safranal.
Comparative Study of Solar Drying of Vegetables and Spice Materials with Open Sun Drying
2014
Generally farmers of India dried food and spices for preserving them for a long time, earlier they used to dry the product in open sun drying by spread the product on the ground. They are during it for a long decade but this method is not good or hygienic and that result in significant loss in product, specially dist, dirt, insect, animal, and human interference affect the produce. For saving the products from these kinds of losses and problem many different technologies are developed like different kind of solar dryer. In this research we are comparing three different methods of drying these are direct radiation solar dryer, indirect radiation solar dryer and open sun drying of the product. This research was conducted in Centre of Excellence, Solar energy Research & Utilization Gyan Vihar University Jaipur (raj.). In this research mainly we dried the spices and comparing the drying rate and dryer efficiencies in all three kind of drying methods. This research was conducted in May-J...