Facts and mistakes about milk and dairy products in human nutrition

Mlijeko i mliječni proizvodi - hrana za koju smo sigurni daje dobro poznajemo. Ali, je li to istina? Ovo je često pitanje potrošača, ali i prehrambenih stručnjaka. Zašto? Sve je više stručnjaka i "stručnjaka " koji pišu o korisnom i štetnom djelovanju mlijeka i mliječnih proizvoda u prehrani. Njihova suprotna stajališta posljedica su jednostranog promatranja vrlo složenog područja - prehrane. Svaki stručnjak proučava mlijeko samo sa svog stajališta i zbog toga daje ograničene zaključke. Na primjer - proučavanje djelovanja jednog nutrijenta u mliječnoj hrani, kao što je mast na nivo lipida u krvi, važno je za upoznavanje mehanizma učinka i odgovora, ali ima malu praktičnu vrijednost. Uhrani kompleksne interakcije između nutrijenata mogu promijeniti utjecaj pojedinog nutrienta na nivo lipida u krvi. Upravo s tog stajališta promatrana je u ovomu radu uloga mlijeka i mliječnih proizvoda u prehrani.Milk and dairy products - food for which we are sure that is well known. But is that true? This is today the frequent question of the consumers or even of the nutrition experts. Why? Probably because there are more and more experts and »experts« writing about the beneficial or harmful role of milk and milk products in human nutrition. Unfortunately their statements are frequently controversial. How is this possible? Most likely this is the consequence of limited treating such a complex field as the nutrition is. Milk is studied by each expert from his point of view furthermore the information are in general only partial. For example - studies of the effects of single nutrients such as specific fats in dairy foods on blood lipid levels are important for identifying mechanisms underlying observed responses, but are of little practical relevance. In wholefoods, complex interactions occur among nutrients which can modify the impact of a single nutrient on blood lipid levels. From this point of view the milk and milk products are discussed

Bakterije mliječne kiseline kao probiotici

Lactic acid bacteria (LAB) are commonly found on human and animal mucous membranes in dairy products and naturally on some plant surfaces. They are normal residents of the gastrointestinal tract of human beings. Several species are commercially used in production of fermented milks, yoghurt, other dairy and meat products, as well as other foods. The antimicrobial activities of LAB have been known long ago and recognized as important in food fermentations, food preservation and intestinal ecology. The general nutritious effect is scientifically well established and documented but a considerable amount of doubt or scepticism exists in relation to various prophylactic and therapeutic claims attributed to probiotic preparations. This article represents the species of LAB that have been used as human probiotics or in fermented dairy products claimed to promote health.Bakterije mliječne kiseline (BMK) obično se nalaze u mukoznim membranama ljudi i životinja, u mliječnim proizvodima i, naravno, na površinama nekih biljaka. Normalno naseljavaju probavni trakt ljudi. Brojne se vrste upotrebljavaju komercijalno za proizvodnju fermentiranog mlijeka, jogurta, te drugih mliječnih i mesnih, kao i drugih prehrambenih proizvoda. Mikrobicidna aktivnost BMK dugo je već poznata i priznata kao važna u fermentaciji hrane, očuvanju hrane kao i u ekologiji probavnog trakta. Opći hranidbeni učinak znanstveno je dobro utvrđen i dokumentiran, no značajan je broj sumnjivih i postoji skepticizam o terapeutskim i profilaktičkim učincima probiotskih preparata. Članak prikazuje vrste BMK koje se upotrebljavaju kao humani probiotici ili u fermentiranim mliječnim proizvodima kojima se pripisuje koristan zdravstveni učinak

Chemical composition and organoleptic quality of yoghurt from sheep\u27s milk

Cilj istraživanja je bio utvrditi sastav i senzorske osobine jogurta iz ovčjeg, odnosno mješavine kravljeg i ovčjeg mlijeka, te pri tom ispitati upotrebljivost uobičajenog cjepiva za jogurt. Iz rezultata naših pokusa može se zaključiti da je izrada jogurta iz mješavine ovčjeg i kravljeg mlijeka zanimljiva iz više vidika. Proizvod je energetski bogat i ima visoku prehrambenu vrijednost, jer u prosjeku sadrži 3,79 % masti, 4,16 % bjelančevina i 3,12 % laktoze. Zbog visokog % suhe tvari ovčjeg mlijeka, tekstura i konzistencija proizvoda je odlična. Okus proizvoda je specifičan, što mu daje karakter specijaliteta. Uobičajeno cjepivo za jogurt primjerno je i za jogurt iz ovčjeg i miješanog mlijeka, ali uz viši dodatak. Optimalan dodatak cjepiva za jogurt iz ovčjeg i miješanog mlijeka bio je 4 %.Author examined the composition and sensorial characteristics of the yoghurt from cow\u27s, sheep\u27s and mixed (50:50 %) milk. Yoghurt from mixed milk had a specific taste, 3.79 % fat, 4.16 % proteins and 3.12 % lactose. Optimum starters addition for yoghurt from sheep\u27s and mixed milk was 4 %

Possibility of polyphosphates reductions in processed cheese

Proučili smo mogućnosti zamjene fosfata solima za topljenje koje ne sadrže fosfate odnosno mogućnosti smanjenja njihove količine, a da pritom senzorska i reološka svojstva topljenog sira ostanu nepromijenjenima. Utvrdili smo količinu P2O5, reološke parametre te senzorske osobine uz određenje glavnog kemijskog sastava sirnih mješavina i konačnog proizvoda. Izradili smo devet uzoraka topljenog sira. Za referencijski uzorak odabrali smo topljeni sir koji izrađuju po standardnoj tehnologiji u tvornici Mlekopromet Ljutomer. Upotrijebili smo četiri soli za topljenje na fosfatnoj osnovi i četiri emulgatora. Utvrdili smo da su uzorci izrađeni bez fosfata neprihvatljivi, a da su uzorci, kojih je količina P2O5 na jedinicu proizvoda smanjena do 30% na osnovi senzorskog ocjenjivanja postigli prvi razred. Reološke analize su pokazale da su sirevi s dodatkom P2O5 imali više vrijednosti za povratnost tlačne deformacije (I, II) i tlačni otpor (I, II) od sireva bez ili onih sa smanjenom količinom P2O5.The possibility to replace the polyphosphates with emulsifying salts free of polyphosphates or to reduce their quantity in productions of processed cheese without changing their sensorial and rheological characteristics was investigated. The quantity of P2O5, rheological parameters and sensorial characteristics were evaluated with determination of main chemical compositions of cheese mixtures and final products. For reference sample was used processed cheese produced using standard technology in the dairy Mlekopromet Ljutomer. Four soluble salts on the basis of polyphosphates and four emulsifiers were used. The samples made without P2O5 unacceptable. The samples with reduced P2O5up to 30% were sensorily classified as a first class products. The rheological analysis have shown that the samples with addition of P2O5 had higher values of returnable pressure deformation (I and II) and pressure resistance (I and II) than cheese samples without or with reduced content of P2O

The influence of population size of gram-negative psychrotrophs on survival during pasteurization

Na tri izolata vrste Pseudomonas fluorescens izolirana iz pasteriziranog mlijeka proučavali smo utjecaj veličine populacije na kinetiku odumiranja za trajanje pasterizacije mlijeka (63 °C/30 min). Bez obzira na veličinu populacije i pojedine izolate, do najveće redukcije broja stanica došlo je u vrijeme dogrijavanja uzroka do 63 °C (4 min.). Ako je početna populacija bila <10^4 BK/ml ustanovili smo sto postotnu letalnost. Nakon 48 sati skladištenja (7 °C) i u tim uzorcima pasteriziranog mlijeka zapazili smo prisustvo živih stanica.The influence of initial population size on destruction kinetics during milk pasteurization (63 °C/30 min) was studied relative to three Pseudomonas fluorescens isolates from pasteurized milk. The greatest reduction of viable cells was observed during first stage of milk pasteurization to reaching final temperature (63 °C/4 min) for all isolates and every starting population size. When inital population size attained <10^4 CFU/ml lethality determined immediately after pasteurization was 100%. Despite this fact viable cells were observed in all samples of pasteurized milk stored 48 hours at 7 °C

Evaluation of hygienic quality of milk

Članak obraduje mikrobiološku kontaminaciju sirovog mlijeka kod nas i probleme sa kojima smo se suočili uvođenjem higijenske kakvoće mlijeka za određivanje njegove vrijednosti. Istraživanje obuhvaća primjenu reduktazne probe kao testa za ocjenu higijenske kakvoće sirovog mlijeka u našim uvjetima.The paper deals with the microbiological quality of raw milk in Slovenia. The problems associated with system of payment based on the hygienic quality of milk are discussed. The methilen blue reduction test as indicator of hygienic quality of milk under the system of milk collection in our country was evaluated

The influence of the beta-galaktosidase enzyme on milk coagulation using Streptococcus thermophilus

Određivali smo utjecaj enzima beta-galaktozldaze na količinu kiselina, koju su proizvele bakterijske stanice sojeva Str. thermophllus izoliranih iz mljekarskih kultura, razgradnjom laktoze, i s tim u vezi njihov utjecaj na brzinu grušanja mlijeka. Rezultati su ukazali na izravnu vezu između tri varijable u uvjetima temperature 42 °C, koja se pokazala optimalnom. Spora je varijanta sadržala samo 61 % broja jedinica beta-galaktozldaze na bakterijsku stanicu, i samo 54% proizvedene kiseline brze varijante. Vrijeme grušanja spore varijante bilo je dvostruko dulje nego brze.Study relative to strains of bacterium St. thermophilus isolated from dairy starter cultures, the effect of a certain quantity of beta-galactosidase enzyme on content of acid formed by bacterial cells in the course of lactose disintegration and the speed of milk coagulation was undertaken. The results indicate immediate connection between three mentioned variables. The temperature of 42 ° C proved to be optimal, and under such condition only 61% of the number of beta-galactosidase units per bacterial cell were determined and only 54% acid was produced using slow variant in comparison with the fast one. The lenght of milk coagulation was twice as long using slow variant instead of the fast one

Promjene mikrobiološkog i kemijskog sastava kozjeg mlijeka tijekom druge laktacije

Individual milk samples from the evening and morning milking, of 10 Alpine goats, were taken twice a month from June to November 1999. The goats were in the third month of lactation. 200 milk samples were analysed for standard plate count, coliforms, proteolytic bacteria, sporeforms and chemical composition. Milk production was followed individually for each goat. Milk contained on average 5,65x100000 cfu/mL of total count, 2,04x10000 cfu/mL of coliforms, 3,57x10000 cfu/mL of proteolytic bacteria and 20 cfu/mL of sporeforms. Daily milk production decreased during the first month of milking (the third month of lactation) and then remained constant. The average milk production was 1177 mL/doe/day. Concentration of all measured milk components (fat, total protein, solids non-fat and total solids), with the exception of lactose, increased slightly. Overall mean of chemical composition was 3.33 % fat, 2.69 % total proteins, 4.14 % lactose, 7.63 % solids non-fat and 10.96 % total solids.Dva puta mjesečno, od lipnja do studenoga 1999 (tri tjedna nakon prve mužnje), oduzimani su pojedinačni uzorci večernjeg i jutarnjeg mlijeka od 10 koza srnaste pasmine. U 200 uzoraka mlijeka analiziran je ukupan broj mezofilnih, koliformnih i proteolitičkih bakterija te spora, i kemijski sastav mlijeka. Kod pojedinačne koze praćena je i proizvodnja mlijeka, odnosno mliječnost. Mlijeko je u prosjeku sadržavalo 5,65x100000 mezofilnih aerobnih bakterija/mL, 2,04x10000 koliformnih bakterija/mL, 3,57x10000 proteolitičkih bakterija/mL i 20 spora/mL. Proizvodnja mlijeka smanjila se je u prvom mjesecu mužnje, da bi nakon toga ostala nepromjenjena. Prosječna dnevna proizvodnja mlijeka je bila 1177 mL/kozi. Koncentracija svih analiziranih sastojaka mlijeka (mliječna mast, bjelančevine, suha tvar bez masti i suha tvar) s izuzetkom laktoze, lagano se povećavala. Mlijeko je u prosjeku sadržavalo 3,33 % masti, 2,69 % bjelančevina, 4,14 % laktoze, 7,63 % suhe tvari bez masti i 10,96% suhe tvari