The viability of
Bifidobacterium bifidum BB-12 and
Lactobacillus acidophilus LA-5 microencapsulated by either an extrusion or an emulsion technique and used in white-brined cheese was monitored. Both ...microencapsulation techniques were effective in keeping the numbers of probiotic bacteria higher than the level of the therapeutic minimum (>10
7
cfu
g
−1). While the counts of probiotic bacteria decreased approximately 3
log in the control cheese in which probiotics were used as free cells, the decrease was more limited in the cheeses containing microencapsulated cells (approximately 1
log). Medium- and long-chain free fatty acid contents of the cheeses with immobilized probiotics were much higher than in the control cheese. Similarly, cheeses made with immobilized probiotics contained higher acetaldehyde and diacetyl levels than the control. Experimental cheeses containing microencapsulated probiotics were not different from the control cheese in terms of sensory properties.
The quality criteria of Tulum cheese produced from cow's milk and preserved by the activation of the lactoperoxidase system (LP‐s) were investigated during the 90‐d ripening period. Samples of milk ...containing 20:20 ppm (C), 60:60 ppm (D), and 0:0 ppm (B) SCN:H2O2 were stored at 25°C for 8 hr. As a control (A), one portion of the milk without SCN:H2O2 was stored at 4°C for 8 hr. Total dry matter, fat, salt, total nitrogen (TA), water‐soluble nitrogen (WSN), titratable acidity (% L.A), pH, ripening index, volatile fatty acids, tyrosine, acid value, free fatty acids, total bacteria, and coliform bacteria contents were determined after 1, 30, 60, and 90 d of storage. The effect of the treatments on titratable acidity, tyrosine, volatile fatty acid, acid value, free fatty acids, total and coliform bacteria was statistically significant. LP‐s treatment did not affect fat, dry matter, total nitrogen water‐soluble nitrogen contents of cheese.
Practical applications
The raw milk preserved by adding 20:20 ppm SCN:H2O2 was suitable for producing Tulum cheeses based on the technological processes and quality characteristics of the product, and was concluded that milk with 60:60 ppm SCN:H2O2 can also be used for the production of this kind of cheese.
This study investigated the physical, chemical and sensory characteristics of non-fat yogurts treated with microbial transglutaminase (MTGase) at varying concentrations from 0 to 0.5
g
L
−1. Also, ...the effect of enzyme inactivation prior to fermentation on the selected properties of the yogurts was studied. Acid development rate was reduced with increasing MTGase doses. Cross-linking of milk proteins by MTGase had a growth-slowing effect on yogurt starter bacteria, which was more pronounced at higher concentrations. Physical properties of the yogurts were improved by MTGase throughout 21-day storage; on the contrary, the production of acetaldehyde was slowed down by increasing MTGase concentrations during the same period. Principal component analysis (PCA) and hierarchial cluster analysis (HCA) clearly differentiated the samples with added MTGase at lower (⩽0.3
g
L
−1) and higher (0.4–0.5
g
L
−1) concentrations regarding the physical and sensory properties. The physical and sensory properties of non-fat set yogurt could be improved by incorporating MTGase up to a level of 0.3
g
L
−1.
► This research gives to literature new knowleges about the oxidative and lipolytic stability of Yayık butter produced from different mammals milks (cow, sheep and goat). ► Total amount of free fatty ...acids in cow’, sheep’ and goat’ Yayık butters are significantly different. ► Goat’ Yayık butter have poor oxidative stability and accumulation of free fatty acids is higher in sample GYB than in samples CYB and SYB. ► Cow’ and sheep’ Yayık butter shared almost identical sensory scores during 30days storage, while goat’ Yayık butter in which some flavour defects were detected, had lower scores.
Yayık butter, made from yoghurt, is one of the traditional dairy products in Anatolia In this study, some properties of Yayık butter produced from cow, sheep, and goat yoghurts have been observed during 30days of storage at 4–5°C. In this purpose yoghurts were produced from different species milks then these yoghurts were used as a raw material for production of Yayık butters samples. On the first day of the storage, differences in pH of serum among the butter produced from different mammals were statistically significant. The highest value of lactic acid was measured in the sample of sheep butter (SB). The level of lactic acid in Yayık butters was significantly different. Goat butter (GB) had weaker oxidative stability and significantly higher peroxide value than those of other samples. The highest accumulation of the free fatty acids has been detected in sample GB. All samples of Yayık butter received almost the same score on the first day of the storage, but on day 30 some flavour defects in sample GB were noted by the panelists.
In this study, acetaldehyde, acetone, pH, titratable acidity, lactic acid, tyrosine and free fatty acids, namely butyric acid C4 , caproic acid C6 , caprylic acid C8 and capric acid C10 were taken ...into consideration affecting the variation in aroma and flavour scores AFS of strained yoghurt during the storage period of 60 days. AFS was negatively correlated with acetone r=-0.832, P
The effects of activation of the lactoperoxidase (LPO) system by H2O2–NaSCN and hydrogen peroxide (H2O2) on the accessibility of sulphydryl groups (SH) in skimmed milk, and on the dynamic rheological ...properties of the resulting yoghurt were investigated. Four different concentrations of each reagent (20–80 mg H2O2–NaSCN/kg milk and 100–400 mg H2O2/kg milk) were compared. Clear negative correlations were noted between the accessibility of SH groups and both LPO activation rate and H2O2 concentration. Also the native PAGE pattern of the heat-treated samples showed that with increase in the H2O2–NaSCN and H2O2 concentrations, the level of interaction between β-lactoglobulin (β-lg) and κ-casein (κ-CN) decreased. The complex modulus (G*) of skimmed milk yoghurts declined gradually with the decrease in the concentration of accessible SH groups accordingly. Tan δ values of yoghurt samples were found to be different from the control, but close to each other, indicating that protein interaction forces taking place in the formation of gel networks of treated yoghurts were different from the control.
Yayik butter is one of the traditional dairy products of Turkey. The type of milk used in the manufacture of Yayik butter is one of the most important parameters determining the characteristics of ...the end product. The present study investigated the effects of different milk species (cow, sheep, goat) on some properties of Yayik butters made from yogurts produced using milks of these species. While the sheep Yayik butter had the highest value of lactic acid, the goat Yayik butter had a significantly higher peroxide value than those of cow and sheep Yayik butters, indicating weaker oxidative stability. The accumulation of free fatty acids was highest in goat Yayik butter. On the first day of storage, the use of different milk species did not have any effect on sensory properties of Yayik butters, but some flavor defects in goat Yayik butter were perceived on day 30.
The effect of hydrogen peroxide on the attributes of raw cream was studied. The samples with 500 mg/kg and 1500 mg/kg hydrogen peroxide (H2O2) were compared with an untreated control sample. The ...results indicated that the addition of hydrogen peroxide prevented, to a great extent, the development of lipolysis, proteolysis and acidity, as well as the growth of psychrotrophic microorganisms. However, the treatment had a negative effect on the oxidative stability of the cream.
In this study, the effects of β.D. Galactosidase enzyme preparation which was used in yoghurt manufacturing on some quality criteria of the final product, were investigated. By adding 0.1 ml, 0.2 m1 ...and 0.3 ml enzyme to 1 liter of milk, approximately 30%, 50%, 70% and 90% hydrolysis of lactose were achieved, respectively. In yoghurt samples, obtained by adding enzyme to milk, coagulation time, consistency, titratable acidity, acetaldehyde content and level of tyrosine as well as organoleptic properties were determined during the first and 14 days of storage. Titratable acidity and consistency of yoghurts was not affected by the process of hidrolysis. While acetaldehyde and tyrosine con-tents of the enzyme-treated samples increased. During the storage period, an increase in the level of tyrosine was observed a decrease in the contents of acetaldehyde was found on the contrary. According to the overall score, yoghurt samples, manufactured by hydrolysis, 50% (A) and 70%(B) lactose was found better than the other by the panel members.
Bu çalışmada yoğurt üretiminde kullanılan β D Galaktosidaz enzim preparatının ürün kalite kriterleri üzerine olan etkileri incelenmiştir. 0.1, 0,2 ve 0,3 ml/lt enzim ilave edilerek yaklaşık % 30, 50, 70 ve 90 laktoz hidrolizasyonu sağlanmıştır. Enzimin süte ilavesiyle hazırlanan yoğurtların pıhtılaşma süresi, depolama sürecinde l. ve 14.günlerde konsistens, titrasyon asitliği, asetaldehit ve tirozin değerleri saptanmış ve duyusal değerlendirmeleri yapılmıştır. Laktoz hidrotizasyonunun pıhtılaşma süreleri üzerine kısaltıcı etkisi önemli, titrasyon asitliği ve konsistens değerleri üzerine olan etkisi ise önemsiz bulunmuştur. Enzimle işlem görmüş örneklerin 1. günde asetaldehit ve tirozin değerlerinde artış meydana gelmiştir. Depolama sürecinde tirozin değerleri artarken, asetaldehit miktarları azalmıştır. Toplam duyusal değerlendirmelerde ise panelistler % 50 (A) ve % 70 (B) hidrolizasyon sağlanan örnekleri daha çok beğenmişlerdir.
In this study, some quality criteria of White pickled cheeses produced from milks preserved by the activation of the LP system were investigated during the ripening period of 90 days. For this ...purpose, milks that contained 20:20 ppm (A) and 60:60 ppm (B) SCN-:H2O2 were stored at 30 oC. For the control (K) study one part of milk without addition of SCN-:H2O2 was stored at 4 oC for 6 hours. Afterwards, White cheeses were produced by using this milks. The amounts of SCN-:H2O2 that added to milks were determined by pre-experiments. Total dry matter, fat, fat in dry matter, salt, total nitrogen, soluble nitrogen and thiocyanate contents and titratable acidity (oSH), pH, ripening index, curd firmness values of cheeses were determined during the 1., 30., 60. and 90. days of storage. Organoleptic properties of these cheeses were examined during the 30., 60 and 90. days of storage. According to the results from analyses, for all parameters examined, differences between cheese samples K and A were not statistically significant (p>0.05). Although there was no statistically significant difference between cheese sample B and the others, in cheese sample B, titratable acidity, TN, WSN, ripening index and curd firmness values were lower than the others. As a result, it is found that, the use of milk preserved by the addition of 20:20 ppm SCN-:H2O2 is suitable for the production of White pickled cheese in view of technological processes and quality characteristics of the product, and its concluded that, despite the lack of some chemical properties of cheese, milks added with 60:60 ppm SCN-:H2O2 can also be used for the production of this kind of cheese.
Bu çalışmada, LP sistemi aktivasyonu ile korunmuş sütlerden üretilen Beyaz peynirlerin bazı kalite özellikleri ve bunların 90 günlük olgunlaşma süresindeki değişimleri incelenmiştir. Bu amaçla, 20:20 ppm (A) ve 60:60 ppm (B) SCN-:H2O2 katılarak 30 oC’de; SCN-:H2O2 katılmadan (K) 4 oC’de 6 saat süreyle bekletilen sütlerden Beyaz peynir üretilmiştir. Sütlere katılan SCN-:H2O2 seviyeleri ön denemelerle belirlenmiştir. Beyaz peynirlerde olgunlaşma süresi boyunca 1., 30., 60., ve 90. günlerde toplam kurumadde, yağ, toplam kurumaddede yağ, tuz, toplam azot (TN), suda çözünen azot (SN) ve tiyosiyanat (SCN-), içerikleri ile titrasyon asitliği, pH, olgunlaşma indeksi ve pıhtı sıklığı değerleri belirlenmiştir. Peynirlerin duyusal özellikleri depolamanın 30., 60. ve 90. günlerinde incelenmiştir. Analiz sonuçlarına göre, incelenen özellikler bakımından K ve A peynir örnekleri arasında önemli bir farklılık belirlenememiştir (p>0.05). Diğer yandan istatistiksel açıdan önemsiz bulunmasına karşın, B peynir örneğinin özellikle asitlik, TN, SN, olgunlaşma indeksi ve pıhtı sıklığı değerleri diğerlerine göre daha düşük bulunmuştur. Sonuçta, Beyaz peynir üretiminde 20:22 ppm SCN-:H2O2 katılarak korunmuş sütlerin kullanılmasının teknolojik işlemler ve ürün kalitesi açısından uygun olduğu saptanmıştır. Bununla birlikte, zorunlu olduğu durumlarda üretilen peynirlerde bazı özelliklerde eksiklikler bulunmasına karşın, 60-60 ppm SCN-:H2O2 katkılı sütlerin de Beyaz peynir üretiminde kullanımı önerilebilir.
