Isıl İşlem Görmüş İçme Sütlerinde (Pastörize, UHT ve Laktozsuz UHT Süt) Hidroksimetilfurfural İçeriğinin Belirlenmesi

Abstract

Maillard reaction (non-enzymatic browning) formed during heat treatment is an important for the quality of foods. Hydroxymethylfurfural (HMF) is an intermediate compound of this reaction and can be changed with temperature during production and storage in dairy products. In this study, the HMF levels of pasteurized and UHT milks with different fat contents were determined. In addition to the effect of hydrolisation of lactose on HMF contents, the composition and colour values of milk samples were also determined. Total HMF values varied from 1.15 to 4.78 µmol/L in pasteurized milk, 2.16 to 12.74 µmol/L in UHT milk and 27.35 to 35.73 µmol/L in lactose hydrolised milk. Although increase in heat intensity resulted in an increase in HMF values, levels were still lower than those in other food products. HMF values of UHT milk slightly increased with an increase in milk fat. The highest level was obtained in lactose hydrolised UHT milk. Moreover, the redness values of lactose hydrolised UHT milks were high.

Determination of the effect of milk fat on the inactivation of Listeria monocytogenes by ohmic heating

“…The differences in HMF values observed from the initial heating processes may be due to brand differences in the milk used. In a study, the HMF content of whole, semi-skimmed, and skimmed milk from different brands were in the range of 4.90±0.27-12.74±0.63, 2.50±0.30-8.89±0.18, 2.16±0.37-7.49±0.11 µM/L, respectively (25). In another study, the total HMF content of commercial UHT and sterilized milk samples with different fat content was in the range of 3.46-5.75 µM/L and 15.52-21.38 µM/L, respectively (14).…”

Ohmic heating application with different electric fields on inactivation of Listeria monocytogenes in protein-enriched cow milk

“…The initial HMF content of UHT milk groups significantly affects HMF content after the ohmic process. A study conducted by Urgu et al (2017) showed that the HMF content of full-fat, semi-skimmed and skimmed UHT milk belonging to different brands was in the range of 315-1606 ng/µL. Morales and Jiménez--Pérez (1999) also stated that the total HMF content of commercial UHT milk samples with different fat contents was in the range of 436-725 ng/µL.…”

Fouling In Heat Exchangers Used In Dairy Industry

“…Çiğ süte, patojen mikroorganizmalar ile normal depolama koşullarında süt ve süt ürünlerinde bozulmaya neden olabilecek mikroorganizmaların inhibe edilmesi ve çeşitli enzimlerin kısmen veya tamamen inaktif hale getirilmesi için ısıl işlem uygulanmaktadır. Süt endüstrisinde kullanılan başlıca ısıl işlem uygulamaları pastörizasyon, sterilizasyon ve termizasyon olarak sıralanabilmektedir [1]. Süt işleme tesislerinde söz konusu ısıl işlem uygulamaları, ısı değiştirici veya eşanjör adı verilen, farklı sıcaklıklardaki iki ya da daha çok akışkanın ısılarının birinden diğerine aktarılmasını sağlayan cihazlarda gerçekleşmektedir.…”