No abstract

In this study, the effects of roasting method, grinding and reduction in oil content on the characteristics of Pistacia terebinthus fruit coffee were investigated. Pistacia terebinthus fruit was roasted by microwave, pan and combined (microwave and convection) methods. The degree of roasting was determined by L*, a*, b* color values. The roasting times were 1,500, 1,900 and 1,620 s for microwave, pan and combined roasting methods, respectively. Cold press was used to reduce the oil content both prior to roasting and after the roasting. The oil content was reduced to around 21.5 % in all roasting methods to approach to that of coffee beans. Powdered Pistacia terebinthus fruit coffee brews were compared with each other and Turkish coffee in terms of aroma, flavor, acidity aftertaste, and overall acceptability. Sensorial analysis results showed that coffee brews prepared by pressing after the roasting process were better than those pressing prior to roasting.

The factors affecting the microwave bleaching of sunflower oil and the interaction between them were investigated and optimized by response surface methodology using a three-factor five-level central composite rotatable design. Microwave power, time and the amount of bleaching clay were selected as independent variables studied in the range of 70-120 W, 2-15 min, and 0.01-0.5%. The dependent variables that measure the bleaching efficiency and oil quality were evaluated as hue angle, chroma and totox value. Optimization was carried out by minimizing totox and chroma and maximizing hue angle. Hue angle, chroma and totox were found as 96.91, 37.66 and 23.31 under optimal conditions. Optimal microwave bleaching was successfully performed by using less bleaching clay (0.4%) and a shorter time (8 min) compared to the current industrial application without any adverse effect on oil quality. Hence, microwave bleaching is thought to be an alternative method for the bleaching of edible oils.

In this research, microwave‐assisted bleaching of olive pomace oil is studied under different conditions. Microwave power, mixing time, and adsorbent dosage are optimized using the response surface central composite design, where the optimum conditions are 102 W, 20.07 min, and 4.15%, respectively. The microwave‐bleached oil is compared with the conventionally bleached oil in terms of color, oxidation parameters, sterol composition, and benzo[a]pyrene content. Microwave‐assisted bleaching of the olive pomace oil is performed by using 17% less adsorbent in an 83% shorter time compared to the conventional method. A bleaching performance comparable to the conventional method is achieved using the microwave‐assisted bleaching technique. Microwave‐assisted bleaching can thus be used as an alternative method for the bleaching of olive pomace oil. Practical applications: The microwave‐assisted bleaching method presents attractive advantages, including a shorter bleaching time and a lower amount of adsorbent used. In this respect, the current research contributes toward the conventional bleaching method in the vegetable oil refinery industry and creates a paradigm for future studies on the bleaching of vegetable oils.

Bitkisel yağlar, içerdikleri ve biyoaktif olarak tanımlanan bileşenler sayesinde sağlık açısından birçok fayda sağlamaktadırlar. Yağlar sadece vücuda enerji sağlamakla kalmayıp, ayrıca vücut ısısının ve dokularının korunmasında, içerisinde çözünen vitaminlerin taşınmasında ve daha birçok önemli fonksiyonların yürütülmesinde rol oynamaktadır. Bitkisel yağlarda bulunan en önemli biyoaktif maddeler arasında bitkisel steroller, karotenler, tokoller, fenolik maddeler ve skualen gibi hidrokarbonlar gelmektedir. Uygulanan rafinasyon şartlarına bağlı olarak, değerli bileşenler kayba uğramakla birlikte, yine rafinasyon şartlarına bağlı olarak yağda meydana gelen reaksiyonlar sonucunda, sağlık açısından risk taşıyan bileşenler de (3-monokloropropan-1-2-diol ve glisidil esterleri) meydana gelebilmektedir. Bu derlemenin ilk kısmında yağ rafinasyon basamakları ve bu süreçler içerisinde fonksiyonel bileşenlerde meydana gelen kayıplar ve nedenleri, ikinci kısmında ise yağ rafinasyonu sırasında meydana gelen zararlı maddelerin oluşumu ve miktarlarının azaltılması konusunda yapılan çalışmalar ele alınmıştır.