Farklı sıcaklık normları ve yoğurt kültürleri uygulanan sütlerden üretilen yoğurtlarda kimyasal niteliklerin belirlenmesi
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Tarih
2013
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Hatay Mustafa Kemal Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Bu çalışmada, yoğurt üretimi için inek sütü (Siyah Alaca), CH1 ve YC350 kültürleri kullanılmıştır. Sütlere inokülasyondan önce 80°C?de 30 dk ve 95°C?de 5 dk olmak üzere iki farklı ısıl işlem uygulanmıştır. Örnekler 80YC350, 80CH1, 95YC350 ve 95CH1 olarak kodlanmıştır. İnokülasyon yapılan sütlerde inkübasyon süresince pH 4.6 değerine ulaşıncaya kadar her saatte bir kimyasal nitelikler tespit edilmiştir. Üretilen set tipi yoğurtlarda ise depolamanın 1., 7., 14. ve 21. günlerinde kimyasal, duyusal ve fiziksel nitelikler saptanmıştır. Uçucu bileşenler statik tepe boşluğu/katı faz mikroekstraksiyon tekniği ile kapiler kolon kullanılarak gaz kromatografisinde, serbest aminoasitler ve organik asitler yüksek performanslı sıvı kromatografisi ile belirlenmişlerdir. Yoğurdun tat ve aromasından sorumlu başlıca uçucu bileşenlerden asetaldehit, asetoin, aseton, diasetil ve etanol bileşenlerinin miktarları üzerine süte uygulanan ısıl işlem normlarının, kültür çeşidi, inkübasyon ve depolama süresinin etkisi önemli bulunmuştur. Hem fermantasyon hem de depolama sırasında en yüksek miktarlarda asetaldehit, diasetil, asetoin ve aseton CH1 kültürünün kullanıldığı örneklerde tespit edilmiştir. Deneme parametreleri örneklerin karbonhidrat ve çoğu organik asit içerikleri açısından önemli farklılıklar (P<0,001) yaratmıştır. Örnek 95CH1 hem fermantasyon hem de depolama sonunda en fazla toplam organik asit (13569?20068 mg/kg) ve en az toplam karbonhidrat içeriğine (37431?36073 mg/kg) sahip olmuştur. Serbest amino asitler yoğurt örneklerinde depolamaya bağlı olarak artmış ve örnekler arasında farklılıklar göstermiştir. Depolama sonunda en yüksek serbest amino asit içeriğine sahip olan örnek 80CH1 (306 mg/kg) olurken en düşük içeriğe sahip olan örneğin 95YC350 (263 mg/kg) örneği olduğu tespit edilmiştir. Panelistler, genel kabul edilebilirlik bakımından en yüksek puanı 80CH1 (5,37) örneğine verirken en düşük puanı ise 80YC350 (4,0) örneğine vermişlerdir. En yüksek puanı alan örnekte titrasyon asitliği, viskozite, serum ayrılması, laktik asit, formik asit, bütanoik asit, asetaldehit, aseton, etanol, diasetil, asetoin sırasıyla %1,23±0,02, 3072 mPas, 5,23 mL, 13011 mg/kg, 4590 mg/kg, 1070 mg/kg, 3,98 mg/kg, 7,98 mg/kg, 36,71 mg/kg, 41,40 mg/kg ve 4,59 mg/kg olarak belirlenmiştir.
In this study, cows?(Siyah Alaca) milk, CH1 and YC350 starter cultures were used for yoghurt production. Before inoculation, two different heat treatment norms, 80°C/30 min and 95°C/5 min, were applied to milk. Samples were coded as 80CH1, 80YC350, 95CH1 and 95YC350. Inoculated milk samples were analyzed for chemical properties at every hour during incubation until pH is reaches the value of 4.6. Produced set yoghurts were analyzed for chemical, sensory and physical properties at 1, 7, 14 and 21 days of storage. The volatile compounds were extracted by using static head space/solid phase microextraction technique and analysed by gas chromatography using capillary column, free amino acids and organic acids were determined by high-performance liquid chromatography. Heat-treatment and type of starter cultures used for yogurt production and incubation, storage time had statistically an effect on acetaldehyde, acetoin, acetone, dicetyl and ethanol compounds which are responsible for the characteristic yoghurt flavour. During incubation and storage, yoghurt with CH1 had acetaldehyde, diacetyl, acetoin and acetone at the highest level. Test parameters had statically an effect on carbohydrate and many of organic acids (p<0.01). The end of fermentation and storage 95CH1 had total organic acid at the highest level (13569?20068 mg/kg) and carbohydrates at the least level (37431?36073 mg/kg). The amount of free amino acid increased in yoghurt due to storage process applied. The end of storage, ıt is determined that 80CH1 had highest free aminoacid (306 mg/kg) and 95 YC350 had also least level (263 mg/kg). Heat-treatment, type of cultures and incubation time had statistically an effect on the organic acids and carbohydrates (P<0.01). During incubation, culture CH1 and heat treatment at 95oC caused an increase in lactic acid content compared to the other parameters. Significant differences among samples during incubation were observed in terms of organic acids, except for butanoic acid. In terms of general acceptability, yoghurts 80CH1 and 80YC350 were received the highest and the lowest scores by panalists. Titratable acidity, viscosity, serum seperation, lactic acid, formic acid, butanoic acid, acetaldehyde, ethanol, diacety and acetoin for yoghurt 80CH1 were: 1,23±0,02% (L.A), 3072 mPas, 5,23 mL, 13011 mg/kg, 4590 mg/kg, 1070 mg/kg, 3,98 mg/kg, 7,98 mg/kg, 36,71 mg/kg, 41,40 mg/kg and 4,59 mg/kg, respectively.
In this study, cows?(Siyah Alaca) milk, CH1 and YC350 starter cultures were used for yoghurt production. Before inoculation, two different heat treatment norms, 80°C/30 min and 95°C/5 min, were applied to milk. Samples were coded as 80CH1, 80YC350, 95CH1 and 95YC350. Inoculated milk samples were analyzed for chemical properties at every hour during incubation until pH is reaches the value of 4.6. Produced set yoghurts were analyzed for chemical, sensory and physical properties at 1, 7, 14 and 21 days of storage. The volatile compounds were extracted by using static head space/solid phase microextraction technique and analysed by gas chromatography using capillary column, free amino acids and organic acids were determined by high-performance liquid chromatography. Heat-treatment and type of starter cultures used for yogurt production and incubation, storage time had statistically an effect on acetaldehyde, acetoin, acetone, dicetyl and ethanol compounds which are responsible for the characteristic yoghurt flavour. During incubation and storage, yoghurt with CH1 had acetaldehyde, diacetyl, acetoin and acetone at the highest level. Test parameters had statically an effect on carbohydrate and many of organic acids (p<0.01). The end of fermentation and storage 95CH1 had total organic acid at the highest level (13569?20068 mg/kg) and carbohydrates at the least level (37431?36073 mg/kg). The amount of free amino acid increased in yoghurt due to storage process applied. The end of storage, ıt is determined that 80CH1 had highest free aminoacid (306 mg/kg) and 95 YC350 had also least level (263 mg/kg). Heat-treatment, type of cultures and incubation time had statistically an effect on the organic acids and carbohydrates (P<0.01). During incubation, culture CH1 and heat treatment at 95oC caused an increase in lactic acid content compared to the other parameters. Significant differences among samples during incubation were observed in terms of organic acids, except for butanoic acid. In terms of general acceptability, yoghurts 80CH1 and 80YC350 were received the highest and the lowest scores by panalists. Titratable acidity, viscosity, serum seperation, lactic acid, formic acid, butanoic acid, acetaldehyde, ethanol, diacety and acetoin for yoghurt 80CH1 were: 1,23±0,02% (L.A), 3072 mPas, 5,23 mL, 13011 mg/kg, 4590 mg/kg, 1070 mg/kg, 3,98 mg/kg, 7,98 mg/kg, 36,71 mg/kg, 41,40 mg/kg and 4,59 mg/kg, respectively.
Açıklama
Anahtar Kelimeler
Gıda Mühendisliği, Food Engineering, Yoğurt, KFME, uçucu bileĢenler, organik asitler, amino asitler, sıcaklık uygulaması, starter kültür, Yoghurt, SPME, GC, volatile compounds, organic acids, amino acids, heat treatment, starter culture
