Food science and technology, like many other science-based disciplines, has advanced rapidly since the fourth edition was published in 1986. Although many of the basic unit operations have changed little, new knowledge and concerns about biotechnology and foods, food safety, environmental issues, packaging technologies, government regu lation, globalization of foods, nutrition, and others, as well as new processing technolo gies such as ohmic heating and supercritical fluid extraction, have emerged. Many of the changes and additions to the fifth edition of Food Science reflect these and other developments which increasingly influence all involved in food processing as well as government agencies around the world. However, true change can only be measured against the broad principles and conventional food production practices of proven value. Therefore, most basic principles and practices continue to be described at an appropriate introductory level in the fifth edition. Oziq-ovqat fani va texnologiyasi, boshqa ko'plab ilmiy asoslangan fanlar kabi, to'rtinchi nashri 1986 yilda nashr etilganidan beri tez rivojlandi. Garchi asosiy birlik operatsiyalarining ko'pchiligi ozgina o'zgargan bo'lsa-da, biotexnologiya va oziq-ovqat mahsulotlari, oziq-ovqat xavfsizligi, ekologik muammolar haqida yangi bilim va xavotirlar. , qadoqlash texnologiyalari, davlat tomonidan tartibga solish, oziq-ovqat mahsulotlarining globallashuvi, ovqatlanish va boshqalar, shuningdek, ohmik isitish va superkritik suyuqliklarni olish kabi yangi qayta ishlash texnologiyalari paydo bo'ldi. Oziq-ovqat fanining beshinchi nashriga kiritilgan ko'plab o'zgartirish va qo'shimchalar ushbu va boshqa o'zgarishlarni aks ettiradi, ular oziq-ovqat mahsulotlarini qayta ishlash bilan shug'ullanadigan barcha ishtirokchilarga, shuningdek, butun dunyo bo'ylab davlat idoralariga tobora ko'proq ta'sir qiladi. Biroq, haqiqiy o'zgarish faqat tasdiqlangan qiymatga ega bo'lgan keng tamoyillar va an'anaviy oziq-ovqat ishlab chiqarish amaliyotlari bilan o'lchanishi mumkin. Shu sababli, ko'pgina asosiy tamoyillar va amaliyotlar beshinchi nashrda tegishli kirish darajasida tasvirlangan.