Food Engineering / Gıda Mühendisliği

Permanent URI for this collectionhttps://hdl.handle.net/11147/12

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  • Article
    Citation - WoS: 3
    Citation - Scopus: 5
    Assessing the Impact of Non-Thermal and Thermal Treatment on the Shelf-Life of Onion Juice
    (Czech Academy of Agricultural Sciences, 2018) Demir, Hande; Yıldız, Mustafa Kemal; Becerikli, İsmail; Ünlütürk, Sevcan; Kaya, Zehra
    Onion (Allium cepa L.) juice is a marinating agent for meat and fish marination and readily usable sauce for any meal that has onion in its formulation. This study aims to assess the microbiological and physicochemical changes in the onion juice processed by UV-C irradiation (0.5 mm sample depth, 30 min exposure time, 7.5 mW/cm(2) UV incident intensity) and conventional heat treatment (74.5 degrees C, 12 min) during its storage. Microbiological results showed processing by UV-C irradiation or heat treatment under optimum conditions extended the microbial shelf-life of untreated onion juice by minimum 6-times. Total colour change of heat-treated samples was lower than that of untreated and UV-C treated samples for 12 weeks. Also, pH, total titratable acidity, total soluble solids content, turbidity, NEBI and total phenolic content were monitored for 12 weeks. The results of this study will form scientific infrastructure for onion juice manufacturers to decide on the processing method with respect to its shelf-life.
  • Article
    Citation - WoS: 59
    Citation - Scopus: 71
    Microbial Safety and Shelf Life of Uv-C Treated Freshly Squeezed White Grape Juice
    (John Wiley and Sons Inc., 2015) Ünlütürk, Sevcan; Atılgan, Mehmet Reşat
    The effects of UV-C irradiation on the inactivation of Escherichia coli K-12 (ATCC 25253), a surrogate of E. coli O157:H7, and on the shelf life of freshly squeezed turbid white grape juice (FSWGJ) were investigated. FSWGJ samples were processed at 0.90 mL/s for 32 min by circulating 8 times in an annular flow UV system. The UV exposure time was 244 s per cycle. The population of E. coli K-12 was reduced by 5.34 log cycles after exposure to a total UV dosage of 9.92 J/cm2 (1.24 J/cm2 per cycle) at 0.90 mL/s flow rate. The microbial shelf life of UV-C treated FSWGJ was extended up to 14 d at 4 °C. UV exposure was not found to alter pH, total soluble solid, and titratable acidity of juice. There was a significant effect (P < 0.05) on turbidity, absorbance coefficient, color, and ascorbic acid content. Furthermore, all physicochemical properties were altered during refrigerated storage. The microbial shelf life of FSWGJ was doubled after UV-C treatment, whereas the quality of juice was adversely affected similarly observed in the control samples. Practical Applications: UV-C irradiation is a non-thermal method used for processing of fruit juices with a minimal or no changes in flavor, essential nutrients, and vitamins. Fresh grape juice is a popular drink, usually consumed at summer time due to many beneficial health effects. Although thermal pasteurization is widely used for extending the shelf life of fruit juices, it causes a "cook taste" in grape juice. The applicability of UV-C irradiation as an alternative to thermal pasteurization was investigated. It is concluded that UV-C treatment can be used for extending the shelf life of fresh grape juice.
  • Conference Object
    Risk Management in Production of Egg-Pasta
    (Technical Research Center of Finland, 2009) Baysal, Ayşe Handan; Gennaris, Savvas; Likar, Primoz; Peterka, Darja; Popescu, Oana; Veskus, Tiina
    Pasta (Italian for "dough") is a generic term for Italian variants of noodles, food made from a dough of flour, water and/or eggs. The word can also denote dishes in which pasta products are the primary ingredient, served with sauce or seasonings. There are approximately 350 different shapes of pasta. Examples include spaghetti (solid, thin cylinders), maccheroni (tubes or hollow cylinders), fusilli (swirls), and lasagne (sheets). Two other noodles, gnocchi and spätzle, are sometimes considered pasta. They are both traditional in parts of Italy. Pasta is categorized in two basic styles: Dried and fresh.