Central Institute of Post Harvest Engineering and Technology, P.O. P.A.U. Campus, Ludhiana, Punjab, India.
Crit Rev Food Sci Nutr. 2012;52(9):781-94. doi: 10.1080/10408398.2010.509552.
Cryogenics is the study of very low temperature and its application on different materials including biological products. Cryogenics has numerous applications in space science, electronics, automobiles, the manufacturing industry, sports and musical instruments, biological science and agriculture, etc. Cryogenic freezing finds pivotal application in food, that is, spices and condiments. Although there is a wide range of cryogens to produce the desired low temperature, generally liquid nitrogen (LN₂) is used in food grinding. The application of low temperature shows a promising pathway to produce higher quality end product with higher flavor and volatile oil retention. Cryogenic grinders generally consist of precoolers and grinder with the cryogen distribution system. In such grinding systems, cryogens subject the raw material up to or lower than glass transition temperature before it is ground, thus eliminating much of the material and quality hassles of traditional grinding. At present, the capital investment including cryogen and handling costs escalate the final cost of the product. Thus, for large-scale production, a proper design to optimize and make it feasible is the need of the hour and understanding the behavior of different food materials at these low temperature conditions. This article reviews the scenario and application of cryogenics in different sectors, especially to spice grinding.
低温学是研究极低温度及其在包括生物制品在内的不同材料上的应用的学科。低温学在空间科学、电子、汽车、制造业、运动和乐器、生物科学和农业等领域有众多应用。低温冷冻在食品中具有重要应用，例如香料和调味料。虽然有多种制冷剂可以产生所需的低温，但在食品研磨中通常使用液氮（LN₂）。低温的应用为生产更高质量、更高风味和更多挥发性油保留的最终产品提供了有前途的途径。低温研磨机通常由预冷器和带有制冷剂分配系统的研磨机组成。在这种研磨系统中，制冷剂将原材料冷却到或低于玻璃化转变温度，然后进行研磨，从而消除了传统研磨中的许多材料和质量问题。目前，包括制冷剂和处理成本在内的资本投资推高了产品的最终成本。因此，对于大规模生产，需要进行适当的设计以优化并使其可行，并了解不同食品材料在这些低温条件下的行为。本文综述了低温学在不同领域的应用，特别是在香料研磨方面的应用。
