Variation of Microbiological Properties, Water Activity and Ropiness of White and Whole Meal Breads Under Different Storage Conditions (Turkish with English Abstract)

Abstract

 In this study, white and whole meal breads baked at laboratory conditions were stored at 4, 25, 37 and 45 ºC for 7 days. Total mesophilic aerobic bacteria (TMAB) counts, mold and Bacillus counts were carried out on these breads at 24 hours intervals. Water activity of the crumb was also determined at the same intervals. Bacillus counts were performed to investigate the development of rope spoilage. Rope spore counts of the raw materials were determined as indicators of the initial load of Bacillus spores in the breads. The moisture, crude protein, crude fat, crude fiber, total ash and non-damaged starch composition of the breads were also determined at day 0 in order to identify the breads analytically. Results showed that, among the raw materials, yeast was the ingredient with the highest load of Bacillus spores. It was found that TMAB count was significantly (P<0.01) affected by the storage time and temperature. In addition to storage time and temperature, bread type also had a significant (P<0.01) effect on Bacillus counts. The results indicated no symptoms of mold growth. It was determined that temperature, bread type and storage time (P<0.01) had a statistically significant effect on aw values.

Keywords

• Bread, rope, Bacillus, TMAB, mold, aw     　　

Farklı Depolama Koşullarında Normal ve Kepekli Ekmeklerin Mikrobiyolojik Özellikleri, Su Aktivitesi ve Sünme Durumunun Değişimi

Abstract

Bu çalışmada laboratuvar koşullarında pişirilmiş normal ve kepekli ekmekler, üretimden sonra 7 gün süreyle 4 farklı depolama koşulunda (4, 25, 37 ve 45 ºC) muhafaza edilmiştir. Her 24 saatte bir ekmeklerde toplam mezofilik aerobik bakteri (TMAB) sayısı, küf sayısı ve sünme (rope) gelişimini takip etmek üzere Bacillus sayısı ve ekmeklerin su aktiviteleri (aw) belirlenmiştir. Ekmeklerin başlangıç Bacillus sporu yükünü belirlemek için ekmek hammaddelerinde sünme spor sayımı yapılmıştır. Üretilen ekmekleri analitik olarak tanımlamak için 0. günde ekmeklerin toplam nem, ham protein, ham yağ, ham lif, toplam kül ve zedelenmemiş nişasta miktarları belirlenmiştir. Elde edilen sonuçlar, hammaddelerden spor yükü en fazla olan unsurun maya olduğunu, ekmeklerdeki TMAB sayısının muhafaza süresi ve sıcaklığından önemli düzeyde (P<0.01) etkilendiğini, Bacillus sayısının bunlara ilaveten ekmek tipinden de etkilendiğini (P<0.01), küf gelişiminin ise olmadığını göstermiştir. Ayrıca sıcaklık derecesi, ekmek tipi ve muhafaza süresinin (P<0.01) aw değerini istatistiksel olarak önemli düzeyde etkilediği belirlenmiştir.

Keywords

• Ekmek, sünme, Bacillus, TMAB, küf, aw  　　  

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