Department: 
Food Science & Technology
Project manager(s): 
Year: 
2020
Financial supporter: 
IROST

Spices are popular all over the world due to the increase in appetite as well as the increase in taste, color and aroma of beverages and foods. Saffron (Crocus Sativus Linnaeus) known as red gold is one of the most expensive and valuable spices in the world. Saffron is mainly used in food industry as a coloring and flavoring substance. Valuable medicinal properties of saffron have also been proven. In this study, the effect of pulsed infrared (PIR) radiation on decontamination of total bacterial count, total yeast mold count, Aspergillus flavus spores, D-values, antioxidant activity and total phenolic content, total energy consumption, effective compounds by By spectrophotometry, FTIR and HPLC, color change, temperature profile and surface morphology were studied by scanning electron microscopy and finally microbial modeling in Sargol Negin saffron. The quality of saffron was determined by examining the amount of changes in safranal, crocin and picrocin and color indices in Sargol Negin saffron. The effect of PIR beam operating parameters, power (250, 350 and 450 watts), sample distance (10, 20 and 30 cm), irradiation time (0-20 minutes) and number of PIR pulses (1, 2 and 3 pulses) were evaluated. Based on the obtained results, in general, with increasing the PIR irradiance and the number of PIR pulses and decreasing the distance, the amount of safranal in Sargol Negin saffron decreased significantly (P <0.05). With increasing PIR irradiance and number of PIR pulses and decreasing the distance, the amount of crocin in Sargol Negin saffron decreased significantly (P <0.05). Also, with increasing PIR irradiance and PIR pulse number and decreasing distance, the amount of picrocrocin in Sargol Negin saffron decreased significantly (P <0.05). Examination of changes in color parameters of Sargol Negin saffron by PIR ray showed that there were no significant changes (P <0.05) in the properties of Sargol Negin saffron and the quality was maintained at an acceptable level. The highest reduction of A. flavus spores was obtained in Sargol Negin saffron 3.769 Log CFU / g with power 350 W, distance 10 cm, time 1.5 min and 3 Pulse / s. The highest reduction in total bacterial count was obtained in Sargol Negin saffron equal to 2.203 Log CFU / g with a power of 350 W, distance 10 cm, time 1.5 min and 3 Pulse / s. The highest reduction of mold and yeast was obtained in Sargol Negin saffron equal to 2.194 Log CFU / g with power of 350 W, distance 10 cm, time 1.5 min and Pulse / s3. The Double Weibull model is the best model with the lowest RMSE and the highest R2 compared to other selected models. The effect of PIR on total phenolic and antioxidant content in Sargol Negin saffron was significant (P <0.05). PIR energy consumption is 50% lower than IR due to the pulsed process. The overall changes of color, chroma and hue in saffron under PIR treatment changed slightly (P <0.05). The highest temperature of 116.5 ºC was obtained in 450PIR power, 10 cm distance, 3 pulses per second and 1 minute in Sargol Negin saffron. According to the results, the PIR method is recommended for food processing because it can maintain the quality of food at an acceptable level.
 

Iranian Research Organization for Science and Technology
Department of Chemical Technologies
Last updated on Aug - 16 2022
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