Free fatty acid content, conjugated dienes content, total phenolic content and turbidity measurements of organically
produced natural olive oil samples were 3.43, 1.06, 43.87, 0.17 for the samples of the 2005 season and 0.88, 0.12,
98.58, 26.61 for the samples of the 2008 season, respectively. During storage, levels of the free acidity and
conjugated diens of olive oil samples increased while their turbidity value and total phenolic content decreased. As the
CIE color values of L and a* increased, b* value decreased during storage. Stored samples had the absorbance
maximum between 240 and 270 nm wavelengths. On the other hand, acidity levels in crude olive pomace oil and 2nd
extraction oil were very high and reduced to acceptable limits after refining. Contrarily, refining reduced total phenolic
content of olive oils significantly. Similarly, refining also reduced turbidity and a* values in the pomace oils. The range
for maximum absorbance was wider for pomace oil samples than the virgin olive oils. In addition, absorbance peaks
at 415 and 670 nm were absent for virgin olive oil samples. In conclusion, virgin olive oils should not be stored more
than 3 years for marketing purposes.
Pesticides are frequently used in modern agriculture to improve production by reducing pest populations. Besides
concerns like environmental pollution and destruction of non-target organisms, there are also health concerns due to
the pesticide residues on foodstuffs. Studies have shown that the oxidants with high redox potential can be used to
minimize or completely eliminate pesticide residues on some of the foods, especially fruits and vegetables.
Toxicological evaluation of the degradation products of pesticides could be helpful to minimize health concerns.
Recently, studies have been extensively focused on the toxicity of degradation products of pesticides. Ozone, one of
the oxidants tested, is a promising agent because of its high residue removal efficiency and spontaneous
decomposition without forming any subresidues. Other oxidants used for this purpose include hydrogen peroxide and
chlorine. In addition, advanced oxidation processes, combination of ozone, hydrogen peroxide, titanium dioxide and
UV, present alternative to oxidants alone for pesticide removal because their combination has high efficiency besides
ease of use, and lack of toxic residues. In this paper, the use of various oxidizing agents to remove pesticide residues
from foodstuffs was reviewed.
The typical aroma of wine is mainly associated with volatile compounds coming from grapes. These compounds are
present in grapes and wines as free or bound forms. Aroma compounds in young wines are mostly in their
glycosidically bound forms. Aroma compounds such as terpens, norisoprenoids, benzene derivatives and straight
chain alcohols can be released by acid or enzymatic hydrolysis. The enzyme group of glucosidases is used for
enzymatic hydrolysis of these compounds. The effect of commercial glucosidase preparations produced from various
microbial sources on white wine aroma has been investigated in many studies. The results showed that the enzyme
preparations with considerable activity of glucosidase could increase the aroma potential of white wine and improve
sensory attributes of wines. Appropriate purification and immobilization procedures must be applied to increase the
activity and stability of glucosidases.
Key Words: White wine, Glucosidase, β-Glucosidase, Aroma
5
Karotenoidlerin Biyoyararlılığı: Etkileyen Faktörler ve Biyoyararlılığın Değerlendirilmesinde Kullanılan Yöntemler
Bioavailability of Carotenoids: Methods Used To Assess Bioavailability and Affecting Factors
Carotenoids, which can not be synthesized by mammals, are fat-soluble antioxidant pigments. Antioxidant and vitamin
A activity of carotenoids are the most important functions depending on consumption and absorption, transport,
metabolic reactions in the body and the storage introduce functional benefits on visual, cancer and heart diseases.
Carotenoid bioavailability is defined as the ratio of absorbed and used carotenoids in the body. Factors affecting the
bioavailability of carotenoids are the physical and biochemical characteristics of carotenoids, metabolic reactions,
carotenoid types and isomers, various food processes that affect food matrix, dietary factors including fiber and fat,
aging, hormonal and genetic factors. This study focused on the structure and stability of carotenoids, methods used to
determine bioavailability of carotenoids and the factors affecting bioavailability.
The use of microwave applications in food industry has increased dramatically over the past few decades. Microwave
heating of any material is based on so called dielectric heating, in which energy is absorbed by ions or molecules that
are either induced or permanent dipoles. Upon exposure to the microwave field, polar molecules and ions align
themselves by the rapidly changing direction of the field, during which heat is generated throughout the material. The
most important characteristic of microwave heating is volumetric heating. In this study, the fundamentals of microwave
technology and microwave assisted-vacuum drying method for foodstuffs are reviewed.
Food safety and quality are the main criteria for food industry. In the recent years, the objective measurement of food
product properties related with shape and color has been achieved by computer vision technology. In this paper,
innovative computer vision technology developed for quality control of various foods was reviewed.