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    Floral authentication of some monofloral honeys based on volatile composition and physicochemical parameters
    (Springer, 2022) Yildiz, Oktay; Gurkan, Hacer; Sahingil, Didem; Degirmenci, Atiye; Kemal, Mehtap Er; Kolayli, Sevgi; Hayaloglu, Ali Adnan
    Twenty four honey samples of eight distinct botanical origins obtained from different regions of Turkey were analyzed in this study. Various physicochemical (glucose and fructose content, color, diastase activity, electrical conductivity, optical rotation, moisture and proline content), biochemical (total phenolic content, total flavonoid content, FRAP antioxidant capacity and DPPH radical scavenging activity) and volatile analytical methods were used for floral authentication of the honeys. Identification of 103 volatile compounds from different chemical classes was carried out using SPME/GC/MS. The availability of physicochemical and volatile identification methods, instead of melissopalynology which is dependent on the researcher's ability and judgment regarding honey classification, was investigated. The results were statistically processed, and principal component analysis (PCA) was applied. The first two principal components explained 98.10% of the total variance, and the PCA produced eight different groups rhododendron, chestnut, lavandula, astragalus, chaste tree, polyfloral, oak, and pine honeys, each corresponding to a distinct botanical origin. Polyfloral honeys formed a cluster, although those samples were rather widespread. The studied honeys exhibited specific volatile compounds and biochemical properties which may be capable of use as floral markers.
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    Properties of Rose Hip Marmalades
    (Faculty Food Technology Biotechnology, 2012) Yildiz, Oktay; Alpaslan, Mehmet
    Rose hip, also known as wild rose, is a summer fruit. The aim of this research is to present physical, chemical, rheological, sensory and antioxidant properties of rose hip marmalades. Rose hips cultivated in Turkey are processed into pulp and then marmalade is made by using vacuum evaporator or classical method. For the purposes of this investigation, marmalades produced on a factory scale using two methods were compared to commercial marmalades purchased on market. The marmalades exhibited high levels of antioxidant activity as well as total phenolic content. The consistency indices for the marmalades were determined to be between 64.2 and 321 Pa.s(n). Colour parameters, namely L, a, b, were measured and correlations between the examined parameters were calculated.