Search

It was reviewed the results of scientific studies on the presence of non-enzymatic browning compounds in bakery products, the mechanism and factors influencing their formation, as well as the prediction and control of the development of browning in baked goods using mathematical modelling. Analytical studies on the mechanism of browning on the surface of bakery products and the prediction and control of the development of browning in bakery products using mathematical modelling based on already available research articles. The formation of colour in bakery products during the baking phase is commonly known as browning. The brown colour on the surface of bakery products comes from melanoidins (an insoluble brown pigment) and caramel, which are products of non-enzymatic browning reactions (Maillard reactions and caramelization). These reactions can also form undesirable products with potentially mutagenic effects (acrylamide, hydroxymethylfurfural and furfural), resulting in a loss of nutritional value of the product. The change in the colour of the surface of the product is considered an essential parameter for determining the end of the baking process of bakery products. Efforts should be made to develop a fast, inexpensive, automated, reasonable and objective method to track colour change during baking. The development of a mathematical model of browning is essential to predict and control this phenomena during baking as a function of operating conditions and the product recipe. Kinetic models for the colour change of bakery products are divided into two groups. The first group consists of kinetic models of colour change where the independent variable is time. This group includes kinetic models of zero, first and second order reactions and the exponential empirical model. The second group consists of kinetic models of colour change where the independent variable is mass loss. Since browning affects the overall quality of food and leads to changes in sensory and nutritional properties (reduction in bioavailability of proteins and amino acids, formation of acrylamide, hydroxymethylfurfural, and formation of substances with antioxidant activity), it is a topic of great interest to food technologists.

Introduction. This review paper deals with literature analysis of modern computer vision and image analysis method in cheese-quality evaluation. Materials and methods. In this paper several cheese types made from cow’s milk were analyzed: soft, semi-hard, and hard cheese respectively. All images shown in this paper were scanned with a flatbed scanner, and images were processed using ImageJ software. Results and discussion. Because with the most part of the external quality attributes evaluation is time-consuming, due to visual inspection, computer vision provides a means to perform this task automatically. To evaluate various cheese external quality properties (color), and defects (mechanical openings – gas holes ; rind defect – formation of calcium lactate crystals and excessive rind halo ; amount and distribution of added ingredients ; meltability and oiling-off) computer vision system has been successfully applied. Image analysis was used for measurement of the normal amount of gas production, and abnormal shape or distribution of eyes throughout the structure of Emmental and Tilsit cheese. Image analysis was used to determine the presence of rind halo cheese defect and to measure the area occupied by calcium lactate crystals on surfaces of naturally smoked Cheddar cheese samples. To improve empirical methods (Arnott and the Schreiber test) and to offer a new approach for evaluation of meltability and oiling-off of Mozzarella cheese, computer vision and image analysis method was applied. In addition, digital image analysis is used for evaluation of the addition of some ingredients and evaluation of the amount and distribution of added ingredients into the semi-cooked cheese with added paprika and herbs. Conclusion. Computer vision and digital image analysis represents an efficient and non-invasive technique able to investigate the cheese optical properties and give information concerning their composition and structure.

The sudden craft breweries expansion currently occurring in Europe, and by that also in Croatia, has been a true conundrum. The question is why craft breweries currently undergo such intense propagation. The answers to this is not simple and has to be monitored from a few different angles: what are today’s consumer’s preferences? Why this sudden need to drink posh beer? Health wise – is it healthier to drink craft beer than industrial? The fact is that craft breweries offer beer with a story. The popularity of health benefits of moderate beer consumption, different reports in popular papers and magazines on polyphenolic and other anti-oxidative compounds that aid catching free radicals and reduce the damage they cause, contribute to the shift from industrial plane lager beer craft beer. In the eye of the scientific storm-genetic manipulation with yeast strains, and barley cultivars, water treatments, automatization, people choose simple procedures and raw materials that give them a feeling of uniqueness. This paper contributes to the knowledge of why craft breweries are taking on more and more popularity and why are consumers attracted to such products.

Introduction. A certain degree of damage to the starch granules is desirable but excessive level of starch damage can have deteriorating effect on the quality of the bakery products. Materials and methods. The wheat flour with lower (3.15%) and higher degree of starch damage (6.13%) were produced by repeat grinding (two passes) in a laboratory mill. The rheological measurements of dough samples were conducted using Farinograph and Extensograph, and gelatinisation and pasting properties – differential scanning calorimetry and Micro Visco-Amylo-Graph. Texture profile analysis of bread samples were performed using a texture analyser, and specific volume by laser topography method. Results and discussion. The dough mixing properties were generally better for the samples with a higher level of starch damage and the most significant improvement has been manifested in the increased water absorption, from 60.7% to 63.8%. Higher water absorption can be associated with the influence of starch damage but also with the effect of flour particle size because smaller particles have larger total surface area. The starch damage had no significant effect on most of the extensographic indicators, although a slight decrease in resistance and extensibility was observed. Samples with a higher degree of starch damage showed decreased gelatinisation power. The gelatinization enthalpy (ΔHg) decreased from 1.41 to 1.31 J/kg, and amylographic peak viscosity from 582.5 to 505.0 BU. This could be explained by the restricted swelling of damaged starch granules due to the loss of organised structure. There were no significant differences in the moisture content and water activity between samples with different damaged starch content. The starch damage had a significant impact on majority of the bread quality parameters but the hardness increase and specific volume were most pronounced. The hardness increased from (from 4.09 N to 5.25 N) and specific volume (from 4.04 cm3/g to 3.53 cm3/g) when flour with a higher degree of damaged starch was used. Conclusions. The level of starch damage had a significant effect on the dough rheological properties, starch gelatinisation and pasting properties, as well as on the bread quality parameters.

The modern food industry relies on the application of the Maillard reaction to produce many foods, e.g. coffee and bakery products that possess the colour and flavour demanded by the consumer. The aim of this study was kinetics modelling of cookie browning during 10 minutes of baking at 205C in order to predict the cookie light-ness variation during baking. Cookies were produced according to AACC Approved Method 10-50D from a commercial cookie plain white flour and wholegrain flour. Baking quality of used flours was determined using Alkaline water retention capacity (AWRC) and Solvent retention capacity (SRC) methods and by measuring width (W), thickness (T), W/T ratio (cookie spread factor) and volume of cookies. Both type of flour was used to make three types of mixing distinguished in water addition (standard-S; dry-D and wet-W formula). The colour of samples was measured using digital image analysis, and quantified using CIEL*a*b* colour model. Several mathematical model was proposed to predict the development of browning during baking (zero-, first- and sec-ond-order kinetics model). Lightness (L*) variation were supposed to be representative of colour formation reac-tion. Comparing all the results of surface and bottom cookies lightness, the cookies with the plain white flour and standard addition of water had the lowest value of lightness change. The evolution of lightness appears to follow a second-order kinetic of cookies made from wholegrain flour, and evolution of lightness of cookies made from plain white flour followed zero-order kinetic. According to obtained results, all tested kinetics model can be used for modelling of cookie browning. Kinetic model is also suitable to suggest how baking profiles should be changed in order to obtain products with a different final lightness.

Slacanac V., Lucan M., Hardi J., Krstanovic V., Koceva-Komlenic D . (2012): Fermentation of honey-sweetened soymilk with Bifidobacterium lactis Bb-12 and Bifidobacterium longum Bb-46: fermentation activity of bifidobacteria and in vitro antagonistic effect against Listeria monocytogenes FSL N1-017. Czech J. Food Sci., 30: 321–329. The influence of the honey addition on the fermentative activity of Bifidobacterium lactis Bb-12 and Bifidobacte rium longum Bb-46 in soymilk was determined. Additionally, the inhibitory potential of honey-sweetened fermented soymilk against Listeria monocytogenes strain was examined. Two monofloral honey types were added to soymilk before the fermentation: dark-coloured chestnut honey and light-coloured acacia honey. On the basis of our previous studies on cow and goat milks, the basic hypothesis of this study was that the addition of honey could influence the growth of Bifidobacterium lactis and Bifidobacterium longum during the fermentation of soymilk. The addition of honey also influenced the decrease of raffinose and stachyose contents during fermentation. Furthermore, a higher inhibitory potential was assumed against Listeria monocytogenes caused by the honey addition. The obtained results show that both types of honey influenced the fermentative activity and numbers of Bifidobacterium lactis Bb-12 and Bifidobacterium longum Bb-46 viable cells in soymilk. Chestnut honey strongly influenced the acidity increase during the soymilk fermentation. A disc assay showed that the development of the inhibition zones of the growth depended on the type and concentration of honey, as well as on the type of milk. The chestnut honey had generally a higher inhibitory effect than acacia honey.

The aim of this study was to determine the influence of goat's milk fermented by Bifidobacterium longum Bb-46 on pathogenic Staphylococcus aureus strain, as well as to determine the differences of inhibitory potential between fermented goat's and cow's milk. The results showed significantly higher inhibitory effect of fermented goat's milk on the growth of Staphylococcus aureus compared to that of fermented cow's milk. Fermented goat's milk inhibited the growth of Staphylococcus aureus during the whole fermentation period. In contrast to fermented goat's milk, weaker inhibitory effect of fermented cow's milk was observed only during the first phase of fermentation (incompletely fermented samples with higher pH values and lower number of viable cells of Bifidobacterium longum Bb-46). The obtained results suggested that there was no correlation between changes of pH or CFU of Bifidobacterium longum Bb-46 during fermentation and the inhibitory effect of fermented cow's and goat's milk. However, the results suggested some correlation between the inhibition of Staphylococcus aureus growth and the content of SCFA and MCFA in fermented cow's milk. At the same time, considerably higher amounts of all examined SCFA and MCFA were produced in goat's milk in all the phases of the fermentation process.

The aim of this study was to use a predictive model to analyse the growth of a probiotic strain Bifidobacterium animalis subsp. lactis Bb-12 in cow’s, goat’s and soy milk. The Gompertz model was used, and the suitability of the model was estimated by the Schnute algorithm. Except for the analysis of Bifidobacterium animalis subsp. lactis Bb-12 growth, the Gompertz model was also used for the analysis of pH changes during the fermentation process. Experimental results, as well as the values of kinetic parameters obtained in this study, showed that the highest growth rate of Bifidobacterium animalis subsp. lactis Bb-12 was obtained in goat’s milk, and the lowest in soy milk. Contrary to the growth of Bifidobacterium animalis subsp. lactis Bb-12, pH decreased faster in soy milk than in cow’s milk. The highest rate of pH decrease was also observed in goat’s milk, which is in correspondence with results of various previous studies. The Gompertz model proved to be highly suitable for analysing the course and the fermentation kinetics in these three kinds of milk, and might be used to analyse the growth kinetics of other probiotic and starter cultures in milk., Cilj rada bio je upotrijebiti jedan od prediktivnih modela rasta bakterija za analizu rasta probiotičkog soja Bifidobacterium animalis subsp. lactis Bb-12 u kravljem, kozjem i sojinom mlijeku. Korišten je Gompertzov model, a prikladnost modela je procijenjena Schnuteovim algoritmom. Osim za analizu rasta Bifidobacterium animalis subsp. lactis Bb-12, Gompertzov model korišten je i za analizu kretanja pH vrijednosti tijekom fermentacije. Eksperimentalni rezultati, kao i vrijednosti kinetičkih parametara, dobiveni u ovom radu, pokazali su da je najveća brzina rasta Bifidobacterium animalis subsp. lactis Bb-12 bila u kozjem mlijeku, a najmanja u sojinom mlijeku. Suprotno u odnosu na rast Bifidobacterium animalis subsp. lactis Bb-12, pH vrijednost opadala je brže u sojinom mlijeku nego u kravljem. Najveći pad pH bio je također u kozjem mlijeku, što potvrđuju rezultati naših prethodnih studija kao i rezultati drugih autora. Gompertzov model pokazao se pogodnim za analizu tijeka i kinetike fermentacije u ove tri vrste mlijeka i može se koristiti za analizu kinetike rasta drugih probiotičkih i starter kultura u mlijeku.

The concentration of the minerals (Ca, Mg and P) and trace elements (Zn, Fe) were determined in goat and cow’s dairy products. The aim of this work was to determine the concentrations of mentioned minerals and trace elements in fermented dairy products made of goat milk, as well as in East Croatia traditional White Slice goat cheese. Obtained results show that goat milk and dairy products from goat milk had higher concentration of Mg and Fe than these of cow milk. Goat milk and dairy products from goat milk also had higher concentration of P, whereas the concentration of Ca was equally in goat and cow milk. However, significantly lower concentrations of Zn in goat milk and goat milk products were determined. Levels of analyzed major and trace minerals were higher in fermented dairy products and cheeses than in liquid milk. The levels of major and trace minerals in White Slice cheese were greater than those in fermented milk products. High content of phosphorus in White Slice goat cheese than in White Slice cow cheese was determined.

Caprine milk is a nutritional and therapeutic food. The unique and beneficial characteristics of caprine milk that are superior to bovine milk include: better digestibility ; greater buffering capacity ; fat globules that are smaller in diameter and better distributed in the milk emulsion ; higher content of short-chain fatty acids in the milk fat ; higher content of zinc, iron and magnesium ; stronger lactoperoxidase (antimicrobial) system as well as better immunological and antibacterial characteristics. The larger amounts of some minerals, such as calcium, zinc and magnesium, in caprine milk may influence the growth of lactic acid bacteria since they are a normal part of some enzymatic complexes involved in lactose fermentation. The higher whey protein content could also be significant because Lactobacillus acidophilus and bifidobacteria grow better in the presence of higher levels of some amino acids (valine, glycine, hystidine). The use of caprine and ovine milk in cheesemaking is well known, but the production of fermented caprine milk via probiotics has not yet been developed, although many studies have highlighted the requirements for production of that kind of healthy food. During fermentation caprine milk loses its characteristic ‘goaty’ taste, which is unacceptable to many consumers. Moreover, the nutritive value of caprine milk increases during fermentation. The rise in the number of goat farms in Croatia has created the need to find other products that can be produced using caprine milk. According to the present situation in Croatia, there is no real possibility of producing fermented caprine milk for the global market, but many studies of fermented caprine milk have been performed.

In general, lactobacilli are nonpathogenic part of the normal urogenital microflora and have been recognized as a barrier against colonization of unwanted (pathogen) microflora. The results of many in vitro studies suggest following mechanisms of probiotic lactobacilli action in urogenital tract: adhesion to urogenital cells, competition with pathogens for adhesive sites, production of biosurfactants, co-aggregation with pathogens, production of antimicrobial substances (organic acids, hydrogen peroxide and bacteriocins) and stimulation of immune system. From 80 different lactobacilli species isolated from human or animal intestinal and urogenital tract, only few lactobacilli strains possess optimal properties to be effective as probiotic therapeutics against infections in the urogenital tract. Combination of Lactobacillus rhamnosus GR-1 and Lactobacillus fermentum RC-14 was proposed as the best one for epithelial vaginal cells colonization and inhibition of uropathogens adhesion. The results of a number of clinical studies confirmed beneficial role of oral lactobacilli. However, the most of commercially available Lactobacillus strains, which are ordinary used in fermented dairy products, are seriously limited in protection of urogenital tract when they are ingested orally., Laktobacili su dio standardne nepatogene normalne urogenitalne mikroflore, koji djeluju kao barijera protiv kolonizacije nepoželjne (patogene) mikroflore. Prema rezultatima mnogih in vitro studija probiotički laktobacili u urogenitalnom traktu mogu djelovati putem sljedećih mehanizama: adhezija na stanice urogenitalnog trakta, natjecanje s patogenima za adhezivna mjesta, produkcija biosurfaktanata, koagregacija s patogenima, produkcija antimikrobnih supstancija (organske kiseline, vodikov peroksid i bakteriocini) i stimulacija imunološkog sustava. U urogenitalnom traktu samo nekoliko sojeva laktobacila, od 80 sojeva laktobacila koji su izolirani iz probavnog i urogenitalnog trakta, ima terapijska svojstva. U kolonizaciji epitelnih stanica vagine i sprječavanja adhezije patogena najuspješnijom se pokazala kombinacija bakterija Lactobacillus rhamnosus GR-1 i Lactobacillus fermentum RC-14. Rezultati niza kliničkih studija potvrdili su blagotvorni učinak oralnog unosa probiotičkih laktobacila. Međutim, najveći broj komercijalno dostupnih Lactobacillus sojeva, koji se uobičajeno koriste za fermentacije u mljekarskoj industriji, ukoliko se unesu oralno imaju limitirano zaštitno djelovanje u urogenitalnom traktu.

The aim of this study was to determine the stimulatory effect of honey addition on fermentation activity of Lactobacillus casei Lc-01 in cow’s and goat’s milk. Two monofloral honey types, dark-colored chestnut and light-colored acacia honey were added to cow’s and goat’s milk before the fermentation. Different mathematical and statistical models were used to describe the kinetics of fermentation in all analyzed samples. The basic hypothesis of this study was that addition of honey could have influence on the fermentation kinetics in both types of milk. Comprehensive kinetic analyses presented in this study suggest complex interaction between all components in fermented milk samples. The results presented in this paper show that addition of the both types of honey had stimulating effect on the growth of Lactobacillus casei Lc-01 in cow’s and goat’s milk. Addition of acacia honey statistically significantly higher stimulated the growth of Lactobacillus casei Lc-01 in cow’s and goat’s milk. This resulted in higher number of Lactobacillus casei cells, as well as in lower pH values of the samples with addition of acacia honey. Furthermore, goat’s milk fermented faster than cow’s milk. Calculated values of selected kinetic parameters show that critical period of the fermentation kinetics, when the honey influenced stimulatory, was between 10th and 20th hour of fermentation.

The aim of the study was to determine the influence of honey addition on fermentation of goat and cow milk with Bifidobacterium lactis Bb-12. Additionally, inhibitory potential of honey-sweetened fermented goat and cow milk against Listeria monocytogenes strain was examined. Two monofloral honey types, dark-colored chestnut and light-colored acacia honey were added. The basic hypothesis of this study was that addition of honey could have influence on the growth of Bifidobacterium lactis during the fermentation of goat and cow milk. Furthermore, higher inhibitory potential caused by honey addition against Listeria monocytogenes has been assumed. Compared to cow milk, higher acidity and CFU of Bifidobacterium lactis Bb-12 were noted in the fermented goat milk in all phases of the fermentation process. The results of this study show that both types of honey enhanced growth and acidity of the Bifidobacterium lactis Bb-12 in both milk types during fermentation. A disc assay has shown that development of growth inhibition zones depends on the type and concentration of honey, as well as on the milk type. The chestnut honey had generally higher inhibitory effect than acacia honey., U radu je ispitivan utjecaj dodatka meda na tijek fermentacije kozjega i kravljega mlijeka probiotičkom bakterijom Bifidobacterium lactis Bb- 12. Također, ispitivan je utjecaj medom zaslađenoga fermentiranoga kozjega i kravljeg mlijeka na inhibicijsko djelovanje rasta bakterije Listeria monocytogenes. Mlijeku su dodavane dvije vrste meda - tamna vrsta kestenova meda i svijetla vrsta bagremova meda. Osnovna pretpostavka u radu bila je da dodatak meda može utjecati na tijek fermentacije kozjega i kravljeg mlijeka, te na brzinu rasta Bifidobacterium lactis Bb-12 u mlijeku. Pretpostavljen je i jači inhibicijski učinak fermentiranog mlijeka na rast Listeria monocytogenes uzrokovan dodatkom meda mlijeku prije fermentacije. Rezultati ispitivanja pokazali su da obje vrste meda poboljšavaju rast i aktivnost Bifidobacterium lactis Bb-12 u obje vrste mlijeka tijekom fermentacije. Istovremeno, u kozjem je mlijeku tijekom cijelog razdoblja fermentacije zabilježena viša kiselost i veći broj stanica Bifidobacterium lactis Bb-12 nego u kravljem mlijeku. Testovi inhibicije rasta bakterije Listeria monocytogenes pokazali su da su veličine zona inhibicije ovisile o svim ispitivanim čimbenicima - vrsti mlijeka, vrsti dodanog meda, kao i o udjelu dodanog meda mlijeku prije fermentacije. Uzorci fermentiranog mlijeka s dodatkom kestenova meda jače su inhibirali rast bakterije Listeria monocytogenes nego uzorci s dodatkom bagremova meda.

Cilj rada bio je ispitati utjecaj fermentacije kozjeg i kravljeg mlijeka ABT- 2 kulturom na promjenu udjela pojedinačnih masnih kiselina u kozjem i kravljem mlijeku. Svrha rada bila je utvrditi povećanje udjela pojedinačnih kratko (SCFA - short chain fatty acids) i srednje (MCFA - middle chain fatty acids) lančanih masnih kiselina tijekom fermentacije kozjeg i kravljeg mlijeka. Hipoteza u radu bila je da veći udjeli SCFA i MCFA tijekom fermentacije ABT-2 kulturom nastaju u kozjem nego u kravljem mlijeku. Rezultati rada pokazali su da se fermentacijski procesi brže odvijaju u kozjem mlijeku u usporedbi s kravljim. Statistički značajno veći broj stanica probiotičkih bakterija Bifidobacterium spp. i Lactobacillus acidophilus La zabilježen je tijekom fermentacije kozjeg mlijeka, uz istodobno brže padanje pH vrijednosti kozjeg mlijeka u odnosu na kravlje. Uslijed fermentativne aktivnosti bifidobakterija iz ABT-2 kulture povećavao se udio SCFA i MCFA u obje vrste mlijeka. Međutim, značajno veći udio mjerenih SCFA i MCFA nastao je fermentacijom kozjeg mlijeka., In this paper, changes in composition and contents of each fatty acid during fermentation with ABT-2 culture were examined. The objective of this study was to determinate the increase of short (SCFA) and medium (MCFA) chain fatty acids in goat's and cow's milk during fermentation with ABT-2 culture. The hypothesis of this study was that higher contents of SCFA and MCFA are produced in goat's milk in comparison with cow's milk, during fermentation with ABT-2 culture. Obtained results have shown that fermentation process in goat's milk is faster than in cow's milk. The number of viable cells of probiotic bacteria Lactobacillus acidophilus La-5 and Bifidobacterium spp. was statistically greater in goat's milk than in cow's milk; consequently, pH value decreased more obviously in goat's milk than in cow's milk during whole fermentation process. Increase of SCFA and MCFA contents during fermentation was noted in both types of milk due to activity of bifidobacteria derived from ABT-2 culture. However, considerably higher amounts of examined SCFA and MCFA were produced in goat's milk than in cow's milk.