Methods for Determination of Surface Tension and Contact Angles of Cooking Oils

Yıl 2014, Cilt: 12 Sayı: 1, 108 - 114, 01.03.2014

Alev Yüksel Aydar Neriman Bağdatlıoğlu

Öz

Surface tension is the force required to stretch a unit change of a surface area 1 cm2. Contact angle is an angle where a liquid/vaporinterface meets a solidsurface. Surface properties are important in the development of new food products and improvement of processes including frying, baking, and emulsification. Deep-fat frying is one of the most common unit operations in food processing in which immersed food and hot oil come into contact at 150–190°C that improves quality and taste of foods. Contact angle and surface tension affect the penetration and wetting properties of oils. Thus, determination of surface properties of vegetable oils at high temperatures plays a key role for understanding oil absorption and heat-mass transfer during frying. In this review, methods for determination of contact angle and surface tension of cooking oils were summarized

Anahtar Kelimeler

Surface tension, Interfacial tension, Contact angle, Cooking oils

Yemeklik Yağların Yüzey Gerilimi ve Temas Açılarının Belirlenmesinde Uygulanan Yöntemler

Öz

Yüzey gerilimi yüzeyin 1 cm2 artırılması için birim uzunluğa uygulanan kuvvet olarak tanımlanmaktadır. Bir katı yüzeyle temastaki bir sıvının oluşturduğu açıya ise temas açısı denmektedir. Gıda endüstrisinde fırınlanma, kızartma, emülsiye etme gibi proseslerin iyileştirilmesinde ve gıdalarda yeni formülasyonların geliştirilmesinde yüzey özellikleri önemli rol oynamaktadır. Kızartma işlemi, genel olarak gıdaların 150-190°C’deki yağ içerisine daldırılarak lezzet ve kalite özelliklerini geliştirmek amacıyla çok eski zamanlardan beri uygulanan en temel işlemlerden birisidir. Temas açısı ve yüzey gerilimi yağın ıslatma ve penetrasyon özelliklerini etkilemektedir. Bu sebeple yemeklik sıvı yağların yüksek sıcaklıkta temas açılarının ve yüzeyler arası özelliklerinin belirlenmesiyle, bunların kızartma süresince ısı-kütle transferi ve yağ absorbsiyonu üzerine etkileri bulunabilinir. Bu çalışmada yüksek sıcaklıktaki yemeklik yağların temas açılarının ve yüzey geriliminin belirlenmesinde uygulanan yöntemler ve çalışmalar derlenmiştir

Anahtar Kelimeler

Yüzey gerilimi, Yüzeyler arası gerilim, Temas açısı, Yemeklik yağlar

Kaynakça

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