No abstract

Gıda üreticileri kaliteyi korumak ve raf ömrünü uzatmak amacıyla koruyucu madde kullanımına ve geleneksel ısıl işlemlere alternatif olarak, minimum işlem görmüş gıdaların üretimine yönelmişlerdir. Bu amaçla doğal antimikrobiyal maddelerin kullanımı tercih edilmektedir. Doğal antimikrobiyal bileşenleri içeren oleoeresinler bitkilerden ekstrakte edilen yağ ve reçine karışımıdır. Bu çalışmada domates çorbası kekik oleoresini ile zenginleştirilerek, domates ürünlerinin ısıl işleminde hedef mikroorganizma olan Bacillus coagulans'a karşı oleoresinin minimum inhibisyon konsantrasyon değeri belirlenmiş, ürünün fiziksel ve kimyasal kalite özellikleri üzerine etkileri saptanmıştır. Domates çorbasında B. coagulans için D90 değeri 3.67 dk. olarak saptanırken, kekik oleoresini içeren çorbada bakteriye ait bu değer 2.58 dk. olarak bulunmuştur. Kekik oleoresinli çorbanın likopen ve parlaklık değerlerinin kontrol (oleoresinsiz) grubuna kıyasla daha yüksek olduğu belirlenmiştir.Food manufacturers have focused on the production of minimally processed foods as an alternative to the use of preservatives and traditional heat treatments in order to protect quality and extend shelf life. Therefore, the use of natural antimicrobials is preferred. Oleoresins which are rich in natural antimicrobials, are a mixture of essential oil and resin extracted from plants. In this study, the tomato soup was enriched with thyme oleoresin, and the minimum inhibition concentration value of oleoresin on the target microorganism, Bacillus coagulans, at heat treatment of tomato based product was determined. The changes on the physical and chemical quality characteristics of the product were determined. The D90 value of the B. coagulans in tomato soup was found as 3.67 min. while this value was found as 2.58 min. for the bacteria in the soup which contains thyme oleoresin. It was concluded that soup with thyme oleoresin had higher lycopene and brightness values than the control (without oleoresin) group.

In this study, organic intermediate moisture raisin was pasteurized with microwave and conventional pasteurization methods. The thermal resistance (D and z values) of the target yeast, Zygosaccharomyces rouxii, was determined for both methods at different temperatures 60°C, 70°C, and 80°C and at different time intervals. The effect of pasteurization methods on the quality properties of raisin samples was investigated. The D values of Z. rouxii were found as 6.50 ± 0.49, 2.96 ± 0.02, 1.91 ± 0.01 min for conventional treatment and 3.46 ± 0.31, 2.02 ± 0.14 and 1 ± 0.01 min for microwave treatment at 60℃, 70℃, and 80℃, respectively. F8537 values for 5‐log reduction and come‐up time significantly decreased after microwave pasteurization. Brix, acidity, and color values were preserved better by microwave treatment. Hydroxymethylfurfural content of the microwave pasteurized samples was found 42% less than the samples pasteurized conventionally. Microwave pasteurization can be alternatively used for the conventional method for raisin improving quality with less heating time. Practical applications Microwave heating needs less come‐up time rather than conventional pasteurization. Decreasing process time provides advantageous via the costs and energy saving so organic intermediate moisture fruits that are perishable can be safely pasteurized by a microwave method for longer shelf life in the industry. Z. rouxii, which may be found in high sugar content foods, can be inactivated to the target log that provides the fruit safe by using this method. In addition, quality properties, such as color, which is effective on the consumer preference also, protected better by the effect of volumetric heating.