Milk is composed of water, proteins, lipids, lactose, vit-amins, and minerals. More than 80% of most mam-mals’ milk proteins are con-stituted by caseins. Casein is a group of proteins and they are sub-divided into αs1-, αs2-, β- and -casein families. Among these ca-sein families, -casein is the second most abundant pro-tein. Different mutations in the cow milk -casein gene led to 12 genetic variants and most common of these are genetic variants A1 and A2. The A1 and A2 variants differ only at amino acid position 67, which is histi-dine in A1 or proline in A2 milk. This difference in amino acid sequence sug-gests a conformational change in the secondary structure of the expressed β-casein. Milk that contains A1 β-casein and A2 β-casein are known as A1 milk and A2 milk, respectively. A1 β-casein milk releases an amino acid bioactive pep-tide called beta-casomorphin-7 (CM-7) in small intestine. Beta-casomorphin-7 released from A1 β-casein is respon-sible for many human dis-orders like type-1 diabetes, autism, schizophrenia, alz-heimer’s disease (AD), at-tention deficit hyperactivity disorder (ADHD), multiple sclerosis (MS) and heart diseases.

Ülkemizde ve dünyada üretilen sütün önemli bir kısmı dayanıklı mamullere işlenmekte ve bu ürünler içerisinde peynir, önemli bir yer tutmaktadır. Peynir, günümüzde çiğ ve/veya pastörize sütten yapılmaktadır. Çiğ sütten üretilen peynirlerin tüketilmesi sonucunda çeşitli enfeksiyon ve intoksikasyon riskleri bulunmaktadır. Bu nedenle endüstriyel olarak üretilen peynirlerin çoğunda pastörize süt kullanılmaktadır. Pastörizasyon işlemi, süt içerisinde bulunan ve ürünün kalitesini olumsuz yönde etkileyecek olan zararlı ve patojen mikroorganizmalar gibi bozulma etmenlerini yok etmektedir. Bu işlem ile peynir üretimi sırasında spontan asitlenmeyi ve peynirin olgunlaşmasını sağlayan laktik asit bakterilerinin de büyük kısmı inaktive olmaktadır. Bu nedenle alışılagelen ve arzu edilen tat ve aromada standart kalitede bir ürün elde edebilmek için peynir üretiminde starter kültür kullanılması teknolojik bir zorunluluktur. Bu derlemede, peynir üretiminde kullanılan starter kültürler ve özellikleri hakkında bilgiler sunulmaktadır.

The aim of this study was to determine and compare certain properties of various butter and butter oils obtained from the province of Hakkari in Turkey. Butter and butter oil samples were produced by local producers using traditional methods from the same raw materials. Fat percentage and total dry matter were determined using the gravimetric method, peroxide values (PV), thiobarbituric acid (TBA), and cholesterol levels were measured using spectrophotometry, and acidity was determined by titration. The water activities (aw) of the samples were measured using a water activity meter. In addition, coliform bacteria, yeast and mould, and lipolytic microorganism counts were determined. Total dry matter and fat values of the butter oils were significantly higher than those of the butter samples. The fat-free dry matter, aw, ADV, cholesterol, and TBA values of the butter samples were generally higher than those of the butter oil samples. The counts of yeast and mould, lipolytic microorganism and coliform bacteria for the butter samples also exceeded those of the butter oil samples. Conversely, peroxide values were higher overall for the butter oil than the butter samples.

Milk is an important food substance and has a complex polydisperse system. The main components of milk consist of lactose, protein, and lipids. Mineral substances and vitamins are also present in milk as minor nutrients. Lactose known as milk sugar is the only carbohydrate in milk and it consists of glucose and galactose. The content of lactose in milk has varied according to milk types. Moreover, it is the most important energy source during the first years of human life, providing almost half of the total energy needed by newborns. Lactose is obtained industrially from the residues of cheese and casein production processes. Lactulose, lactitol, lactobionic acid, galactooligosaccharide, lactosucrose, epilactose, and tagatose are commonly known lactose derivatives. These derivates are produced from lactose using various methods such as epimerization, oxidation, and reduction. In this review, up-to-date information about lactose, lactose derivatives, and the production methods of lactose derivatives are given.