The purposes of this study were to investigate the effects of two different pekmez production methods namely open pan evaporation (OPE) and vacuum evaporation (VE) on the final products, and to observe the changes in constituents as well as aromatic components after 4 months of storage. The initial and poststorage (4 months) 5-hydroxymethyl furfural (HMF) content in OPE apple pekmez were respectively 5.48, and 7.04 mg/kg. No HMF was detected in VE apple pekmez. Both initial and poststorage content of phenolic compounds was higher in VE pekmez compared to OPE pekmez. The effects of production methods and storage time were statistically significant on phenolic compounds in apple pekmez. The content of all analyzed minerals except calcium has significantly decreased in pekmez compared to raw material on dry weight basis. OPE resulted in a 55.97 % loss in the amount of ascorbic acid, whereas the loss in VE has been 23.45 %. Poststorage loss in ascorbic acid has respectively been 69.54, and 89.28 %, for VE and OPE samples. None of the aromatic components of fresh apple was detected in pekmez.

No abstract

547.972Viburnum opulus L., belonging to the plant family of Caprifoliaceae, is known as "gilaburu" in Turkey and "Guelder rose" in Europe. Fruits and fruit juice of V. opulus began to be sold in the markets of Turkey recently. Due to the lack of information in the literature, major organic acids, antioxidant capacity, total phenolic content (TPC), total flavonoid content (TFC), and total anthocyanin content (TAC) as well as some chemical characteristics, including pH, total titratable acidity (TTA), moisture, ash, and oil content of V. opulus fruit flesh and seed were determined. The chemical characteristics of samples are listed in Table 1.Four organic acids in fruit flesh and two organic acids in seed were detected and quantified ( Table 2). The predominant organic acids in fruit flesh and seed were found as malic (86% of total acids) and oxalic (68% of total acids), respectively. The sum of all quantified acids in fruit flesh and seed were 1.25 g/100 g and 0.82 g/100 g, respectively.TPC, TFC, TAC, EC 50 , and ARP values of samples are given in Table 3. Average total phenolic content in V.opulus fruit flesh and seed was 355.59 and 1231.03 mg GAE/100 g FW, respectively. The seed showed about 4 times higher phenolic content compared with fruit flesh. Generally, total phenolic content and antioxidant capacities of fruit seeds were higher than edible portions of fruits. Similar results were reported for tamarind, avocado, jackfruit, longan, and mango (1) and grape seed and grape skin (2). Average total flavonoid content in fruit flesh and seed was 151.70 and 1032.39 mg CE/100 g fresh weight, respectively. These results clearly show that the phenolic content of seed is mainly composed of flavonoids.EC 50 and ARP are widely used parameters to express the antioxidant capacity [3]. The higher the antioxidant capacity, the lower the EC 50 . Average EC 50 values of fruit seed and fruit flesh were found 2.35 mg /mg DPPH· and 24.56 mg/mg DPPH·, respectively. The antioxidant capacity of V. opulus fruit seed was higher than fruit flesh, which is attributable to the amount of phenolic content of fruit seed. The antioxidant capacity of seed was about 10 times higher than fruit flesh, where the total phenolic content of fruit seed was about 4 times higher than fruit flesh. The nonlinear increment in the antioxidant capacity of fruit seed may be due to a proportionally high amount of flavonoids. The proportion of total flavonoids to total phenolics (TFC/TPC) was 0.426 for fruit flesh and 0.838 for seed.In conclusion, fruit seeds have not generally received much attention as antioxidant sources. This may be due to their lack of popularity and commercial applications. Our study shows that the seed of V. opulus is a good source of antioxidants, especially flavonoids, TPC, and TFC, and the antioxidant capacity of seed is significantly higher than that of fruit flesh. Owing to these properties, future studies can be extended to exploit them (especially seed) for their possible application as natural antioxidant for functional food pr...

Keywords: electrolyzed water, microbial reduction, fruits and vegetables

Agricultural products are prone to aflatoxin (AF)-producing moulds (Aspergillus flavus, A. parasiticus) during harvesting, drying, processing and also storage. AF is a mycotoxin that may cause liver cancer when consumed in amounts higher than allowed limits. Figs, like other agricultural products, are mostly affected by AF-producing moulds and these moulds usually produce kojic acid together with AF. Kojic acid is a fluorescent compound and exhibiting bright greenish yellow fluorescence (BGYF) under ultraviolet (UV) light. Using this fluorescence property, fig-processing plants manually select and remove the BGYF+ figs to reduce the AF level of the processed figs. Although manual selection is based on subjective criteria and strongly depends on the expertise level of the workers, it is known as the most effective way of removing AF-contaminated samples. However, during manual selection, workers are exposed to UV radiation and this brings skin health problems. In this study, we individually investigated the figs to measure their fluorescence level, surface mould concentration and AF levels and noted a strong correlation between mould concentration and BGYF and AF, and BGYF and surface. In addition to a pairwise correlation, we proposed a machine-vision and machine-learning approach to detect the AF-contaminated figs using their multispectral images under UV light. The figs were classified in two different approaches considering their surface mould and AF level with error rates of 9.38% and 11.98%, respectively.