Utjecaj različitih probiotičkih kultura na svojstva Torba (čvrstog) jogurta

The viability of Lactobacillus casei LAFTI® L26, Bifidobacterium animalis subsp. lactis LAFTI® B94 and Lactobacillus acidophilus LAFTI® L10, their proteolytic activities and effects on chemical, textural and sensory properties of Torba yoghurts were assessed during 14 days of storage at 4 °C. These probiotic cultures were separately added after the fermentation of milk with yoghurt culture but prior to packaging of the product. Probiotic bacteria reached the recommended level of 6 log cfu/g in Torba yoghurt except B. animalis subsp. lactis B94. The addition of probiotic bacteria resulted in an appreciable proteolytic activity but also textural defects due to the lower total solid content in the final product.Aktivnost Lactobacillus casei LAFTI® L26, Bifidobacterium animalis subsp. lactis LAFTI® B94 i L. acidophilus LAFTI® L10, njihova proteolitička aktivnost i utjecaj na kemijska, teksturalna i senzorska svojstva Torba jogurta procjenjivana su tijekom 14 dana skladištenja na 4 °C. Ove probiotičke kulture odvojeno su dodane nakon fermentacije mlijeka s jogurtnom kulturom, ali prije pakiranja proizvoda. Probiotičke bakterije dosegnule su preporučeni stupanj od 6 log cfu/g u Torba jogurtu osim B. animalis subsp. lactis B94. Dodatak probiotičkih bakterija rezultirao je značajnom proteolitičkom aktivnošću ali i pogreškama u teksturi, što je učinak manjeg udjela ukupne suhe tvari u konačnom proizvodu

Utjecaj korištenja probiotika i prebiotika na aromatske spojeve i teksturalna i senzorska svojstva simbiotskog kozjeg sira

The aim of this study was to evaluate the effects of probiotics as an adjunct culture, and the use of inulin and oligofructose as a prebiotic product, on symbiotic goat cheeses during their ripening period. The control group had the lowest value in terms of aromatic compounds, and the probiotics used in the production of cheese increased the aromatic substances. The control group was found to have the highest hardness values and that the use of prebiotics and probiotic cultures in cheese production significantly changed the textural profile depending on the probiotic and prebiotic type. The most favoured cheeses were found to contain E. faecium and oligofructose.U ovom radu istražen je utjecaj probiotika, te inulina i oligofruktoze, na simbiotski kozji sir tijekom zrenja. U kontrolnoj grupi su utvrđene najniže koncentracije aromatskih spojeva, dok je dodatak probiotika u proizvodnji sira povećao koncentraciju aromatskih spojeva. Također, u sirevima iz kontrolne grupe su utvrđene najveće vrijednosti čvrstoće. Dodatak probiotika i prebiotika je signifikantno utjecao na teksturalne karakteristike sira. Sirevi koji su ocjenjeni kao najbolji, proizvedeni su uz dodatak E. facium i oligofruktoze

Inovativan pristup: kefir na bazi mješavine kravljeg i zobenog mlijeka

The aim of this study was to evaluate the potential of kefir production using cow-oat milk mixture. Therefore kefir samples with 20, 40 and 60 % of oat milk were produced. The effect of oat-milk ratio on physicochemical, rheological, microbiological and sensory characteristics of the kefir samples was studied during 21 days storage at refrigerated conditions. Increasing oat milk concentration affected the whey-off and apparent viscosity by higher whey off and lower viscosity results. Also the proteolytic activity of the samples was decreased by raising the oat milk concentrations. Increase of the oat milk concentration leaded to a decrease of pH of the samples. Statistical analysis showed that the lactococci and lactobacilli viable cell counts differed among the samples while the highest count was detected in sample with the highest amount of oat milk. The control sample (without oat milk) had higher yeast count during the storage period. The final product with 20 % of oat-milk and without addition of flavour was found to be the most acceptable by the sensory panellists. The results indicate the possibility for a new cow/oat milk based kefir.Cilj ovog istraživanja bio je utvrditi mogućnost proizvodnje kefira iz mješavine kravljeg i zobenog mlijeka. Stoga su proizvedeni uzorci kefira s 20, 40 i 60 % zobenog mlijeka. Tijekom 21 dana skladištenja na hladnom ispitivan je utjecaj različitih omjera zobenog i kravljeg mlijeka na fizikalna, reološka, mikrobiološka i senzorska svojstva proizvedenih uzoraka kefira. Povećanje udjela zobenog mlijeka uzrokovalo je povećanje sinereze, smanjenje prividne viskoznosti te smanjenje proteolitičke aktivnosti u uzorcima kefira. Osim toga, povećanje udjela zobenog mlijeka rezultiralo je snižavanjem pH vrijednosti u uzrocima kefira. Statistička analiza pokazala je da se proizvedeni uzorci razlikuju u broju živih stanica laktokoka i laktobacila, s tim da je najveći broj utvrđen u uzroku s najvećim udjelom zobenog mlijeka. Kontrolni uzorak (bez zobenog mlijeka) sadržavao je povećan broj plijesni tijekom cijelog razdoblja čuvanja. Krajnji proizvod s udjelom od 20 % zobenog mlijeka i bez dodatka aroma pokazao se najprihvatljivijim prilikom senzorske ocjene od strane panela. Dobiveni rezultati mogu poslužiti u daljnjem razvoju proizvodnje kefira na bazi mješavine kravljeg i zobenog mlijeka

The effect of using different starter culture combinations on organic and fatty acid compositions of Mihaliç cheese

The objective of this study was to assess the influence of three different starter culture combinations and two scalding temperatures on the organic and fatty acid compositions of pasteurized Mihaliç cheeses. For this purpose, starter culture combinations consisting of Propionibacterium freudenreichii, Streptococcus thermophilus, Lactobacillus helveticus, and Leuconostoc mesenteroides subsp. cremoris were used. Two scalding temperatures, 40 °C or 45 °C, were used for cheeses with the same culture combination. Samples were evaluated in terms of organic and fatty acid compositions during 90 days of ripening. Eye formation, which is a characteristic feature of Mihaliç cheese, was seen in all cheese samples. Propionic and lactic acids were the most abundant organic acids detected in the cheeses. The most abundant saturated fatty acid was palmitic acid, followed by myristic and stearic acids. Oleic acid content was the highest among total unsaturated fatty acids. The control cheese had lower levels of short-chain fatty acids, which contribute directly to the cheese flavour

Farklı inek ve soya sütü karışımlarından üretilen kefirlerin antioksidan özellikleri

Bu çalışmanın amacı inek, soya sütü ve bunların farklı karışımlarından üretilen kefir örneklerinin antioksidan kapasitelerini belirlemektir. Bu amaçla, üretilen kefir örneklerinde askorbat otooksidasyonu, süperoksit anyon radikali ve hidrojen peroksit tutuklayıcı etkileri ile indirgen aktivite gibi antioksidatif özellikler incelenmiştir. Sadece soya sütü ile üretilen kefirler en yüksek askorbat otooksidasyon oranına sahip olmuştur. Kefir örneklerinin sistein eşdeğer miktarı olarak ifade edilen indirgen aktiviteleri istatistiksel olarak farklı bulunmuş ve soya sütü oranın artmasıyla yükselmiştir. İnek, inek/soya ve soya sütlerinden üretilen kefirlere ait süperoksit radikal oluşumunu durdurma sonuçları istatistiksel olarak farklı bulunmuştur. Ancak, gerek kefir tanesi ile gerekse kefir kültürü ile gerçekleştirilen fermantasyonun söz konusu aktivite üzerine etkisi önemsizdir. Elde edilen sonuçlara göre kefir örneklerinin hiçbiri hidrojen peroksit tutuklayıcı etki göstermemiştir.The aim of this study is to determine the antioxidant properties of kefir samples produced from different cow/soy milk mixtures. Antioxidative activities such as the inhibition of ascorbate autoxidation, reducing activity, the scavenging effect of superoxide anion radicals and hydrogen peroxide of kefir samples were determined. Kefirs produced from whole soymilk had the highest inhibition rate of ascorbate autoxidation. Reducing activities of kefir samples, expressed as equivalent amounts of cysteine, were found statistically different and elevated by increased soymilk ratio. Results of the inhibition of superoxide radical generation of cow, cow/soy and soymilk kefir samples were found statistically different. However, the effect of fermentation on this activity neither with kefir grain nor culture was significant. Results indicated that none of kefir samples exhibit a hydrogen peroxide scavenging activity

İnek ve Keçi Sütü Karışımlarından Üretilen Kış Yoğurtlarının Fizikokimyasal ve Duyusal Karakteristikleri

Kış yoğurdu Türkiye'nin Van ve Hatay illerinde en meşhur süt ürünlerinden biridir. Çeşitli sütlerden üretilen kış yoğurdu yüksek kurumadde içeriği ve uzun raf ömründen dolayı "pişmiş yoğurt" veya "tuzlu yoğurt" olarak bilinmektedir. Çalışmada kış yoğurdunun geleneksel olarak üretilmesi amacıyla iki farklı koyulaştırma yöntemi uygulanmıştır. Farklı üretim yöntemlerinin ve depolama süresinin kış yoğurdu örnekleri üzerine etkilerini belirlemek amacıyla 1., 30., 60. ve 90. günlerde bazı fiziksel (sertlik ve yapışkanlık, L-, a- ve b- değerleri), kimyasal (kurumadde, yağ, protein, pH, laktik asit, tuz) ve duyusal (renk, koku, kıvam ve lezzet) analizler yapılmıştır. Kış yoğurdu örneklerinin duyusal ve reolojik özellikleri ile renk değerleri arasında önemli farklıklar bulunmuş, bununla birlikte örneklerin fizikokimyasal özellikleri arasındaki farklar önemsiz olarak tespit edilmiştir. Özellikle % 100 keçi sütünden üretilen kış yoğurtları daha çok beğenilmiştir.Winter yoghurt is one of the most popular dairy products in Van and Hatay region of Turkey. It is made of different kinds of milk, and known as "cooked yoghurt" or "salted yoghurt" due to its high solids content and long shelf life. In this study, two different concentration methods were used to produce traditional winter yoghurt. Some physical (firmness and cohesiveness, L-, a- and b- values), chemical (total solid, fat, protein, pH, lactic acid, salt) and sensory analyses (color, odor, consistent and flavor) were made to determine the effect of production methods and storage on winter yoghurt samples at the 1st, 30th, 60th and 90th days. Significant differences were found between sensory, rheological properties and color values of winter yoghurts however no significant differences were found between physicochemical properties of the samples. Especially, winter yoghurts produced from 100% goat milk were the more appreciated samples