Pawel Glibowski

The Rheological and Instrumental Textural Properties of Selected Table Fats

The rheological and instrumental textural properties of the butters, margarines and spreads were determined in this study. Three factors affected on the rheology and the instrumental texture of the examined yellow fat products: temperature of the measurement, origin and the content of the fat. The results obtained at 5 and 20° C showed significant differences (p ≤ 0.05) in spreadability and hardness. The highest hardness and the lowest spreadability values were recorded for the butters and mixed fat products with high fat content. Generally, milk fat content caused a significant increase of hardness and decrease of spreadability. The best spreadability was measured for the spreads with the lowest fat content. Adhesiveness and cohesiveness analysis revealed that the most adhesive and less cohesive were the products with high fat content, less adhesive and the most cohesive were spreads with the lowest content of lipids. All of the samples exhibited thixotropic and shear-thinning behavior. High correlation was found between spreadability and hardness. Apparent viscosity did not correlate with spreadability and hardness.

A new insight into the physiological role of bile salt hydrolase among intestinal bacteria from the genus Bifidobacterium.

This study analyzes the occurrence of bile salt hydrolase in fourteen strains belonging to the genus Bifidobacterium. Deconjugation activity was detected using a plate test, two-step enzymatic reaction and activity staining on a native polyacrylamide gel. Subsequently, bile salt hydrolases from B. pseudocatenulatum and B. longum subsp. suis were purified using a two-step chromatographic procedure. Biochemical characterization of the bile salt hydrolases showed that the purified enzymes hydrolyzed all of the six major human bile salts under the pH and temperature conditions commonly found in the human gastrointestinal tract. Next, the dynamic rheometry was applied to monitor the gelation process of deoxycholic acid under different conditions. The results showed that bile acids displayed aqueous media gelating properties. Finally, gel-forming abilities of bifidobacteria exhibiting bile salt hydrolase activity were analyzed. Our investigations have demonstrated that the release of deconjugated bile acids led to the gelation phenomenon of the enzymatic reaction solution containing purified BSH. The presented results suggest that bile salt hydrolase activity commonly found among intestinal microbiota increases hydrogel-forming abilities of certain bile salts. To our knowledge, this is the first report showing that bile salt hydrolase activity among Bifidobacterium is directly connected with the gelation process of bile salts. In our opinion, if such a phenomenon occurs in physiological conditions of human gut, it may improve bacterial ability to colonize the gastrointestinal tract and their survival in this specific ecological niche.

Factors affecting inulin crystallization after its complete dissolution

In this study, we analyzed inulin crystallization during one year after its complete dissolution and an effect of inulin crystal seeds concentration on rheological and textural properties of inulin gels. 20% and 25% solutions of three different inulins, one native and two high performance (crystal and amorphous), were prepared by heating at 100°C for 5 min. During one year of storage at 20°C, inulin did not form a gel structure, but only precipitates and a crystal layer on the walls of the containers. Addition of crystal seeds (0.02-2%) caused formation of gel structure. Minimal concentration of the crystal seeds necessary to form a strong inulin gel was 0.4%. Crystallographic structure of inulin powder did not have an influence on the formed gels. The obtained results allow inulin gelation to control which can be crucial in novel foods, the structure of which is based on inulin.

Rheological and sensory properties of stirred yoghurt with inulin-type fructans

This study concerns physicochemical and sensory analysis of stirred yoghurts, in which skim milk powder was partly replaced by different inulins. The composition of basic solutions contained 12% skim milk powder and 4% inulin, while reference yoghurts contained 16% SMP or whole milk powder. Rheological and sensory analysis showed that one-quarter of milk powder could be substituted by long-chain inulin in low-fat stirred yoghurt. Short-chain inulin and oligofructose can potentially be applied in the production of drinking yoghurt. Sensory evaluation showed that milk fat cannot be successfully substituted by inulin.

Effect of Rosemary Transglutaminase on Yoghurt Fortified with Whey Protein Isolate

Abstract Rosemary (Rosmarinus officinalis L.) transglutaminase (RTGase) was used to cross-link whey protein isolate (WPI) and its ability to induce gelation was investigated. The rheological and textural properties of WPI were improved with RTGase treatment. Set-type yoghurts fortified with 1% WPI powder treated with RTGase at the level of 2.5 and 10 unit/g protein were studied. Chemical, rheological, textural and organoleptic properties of the yoghurt treated with RTGase were better than these of the control yoghurt.

Prebiotic and Synbiotic Foods

The aim of this chapter is to review studies where prebiotic substances as well as probiotic bacteria have been applied to foods. Numerous studies have described the application of prebiotics (galactooligosaccharides, soy oligosaccharides, xylooligosaccharides, pyrodextrins, isomaltooligosaccharides, or lactulose) but the most frequently investigated are fructans, such as inulin, fructooligosaccharides, and oligofructose. Prebiotics and probiotic bacteria have been applied in foods, such as dairy products, beverages, bakery goods, meat products, and many others. This chapter shows that symbiotic food, containing both prebiotics and probiotics, can be an alternative to traditional foods. Prebiotic, probiotic, and symbiotic foods can positively affect health and prevent civilization diseases.

THE EFFECT OF REPLACING PORK FAT OF INULIN ON THE PHYSICOCHEMICAL AND SENSORY QUALITY OF GUINEA FOWL PATE

BACKGROUND Potentially, pâtés could be a functional food and are an important source of proteins, vitamin A, B complex vitamins and iron. Unfortunately, one problem in pâtés is the high level of animal fat, about 30%. Pâté with low-fat guinea fowl meat and animal fat replaced with inulin can result in this product being classified as a pro-health food. The objective of the present study was to determine the effect on pâté with guinea fowl meat of reducing its pork back fat content (about 1/3, 2/3 and 100%) and the adding inulin as a partial fat substitute. The effects on the pâtés chemical and physicochemical composition, as well as on its textural characteristics and sensory properties were analysed. METHODS On the day after production, the following took place: chemical analysis: cooking loss, moisture, protein, total fat, total calories, the pH, lipid oxidation were analysed; physical analysis: colour parameters, texture profile analysis and sensory evaluation were analysed. RESULTS The pâté prepared with inulin gels as fat replacers had a fat content reduced (up to 82%), and decreased (up to 58%) energy value. The fat reduction and addition of inulin gels decreased hardness and chewiness, but the pâtés appearance, taste and odour, as well as overall quality were similar to the control (full-fat samples). CONCLUSIONS The study demonstrated that inulin can be used in guinea fowl pâtés as a total fat replacer and a potential source of prebiotic.

Właściwości teksturalne i reologiczne mieszaniny inuliny i tłuszczu mlecznego stabilizowanej lecytyną

S t r e s z c z e n i e Celem pracy bylo porownanie wlaściwości teksturalnych i reologicznych mieszanin otrzymanych na bazie tluszczu mlecznego (15,20 %), inuliny (15, 18, 21, 24 %) oraz lecytyny sojowej (2 %). Emulsje otrzymano sporządzając wodne zawiesiny inuliny, po czym ogrzewano je do temp. 65 °C lub 100 °C, lączono z bezwodnym tluszczem mlecznym o temp. 70 °C oraz lecytyną, a nastepnie homogenizowano. Sporządzone emulsje przechowywano przez 24 h w temp. 5 °C, a nastepnie oznaczano cechy reologiczne oraz teksturalne. Zarowno wlaściwości teksturalne (twardośc, adhezyjnośc, kohezyjnośc, smarownośc), jak i reologiczne (lepkośc pozorna, modul G’ i G”) powstalych emulsji w znacznym stopniu zalezaly od temperatury ogrzewania roztworu inuliny. Badane cechy mieszanin przygotowanych z zastosowaniem zawiesin inuliny ogrzewanej do temp. 65 °C charakteryzowaly sie znacznie mniejszym odchyleniem standardowym w stosunku do ogrzewanych do 100 °C. Prawdopodobną tego przyczyną byla utrata zdolności do krystalizacji inuliny przez jej calkowite rozpuszczenie w 100 °C. Obecnośc tluszczu mlecznego nie wplynela katalizująco na krystalizacje inuliny. Nizsza temperatura umozliwila tworzenie jednorodnej emulsji. Stwierdzono, ze wzrost stezenia inuliny oraz tluszczu mlecznego spowodowal wzrost twardości i zmniejszenie smarowności emulsji oraz ze do wytworzenia emulsji o przewidywanych wlaściwościach teksturalnych i reologicznych konieczne jest stosowanie temperatur umozliwiających krystalizacje inuliny. Slowa kluczowe: inulina, tluszcz mleczny, emulsje, smarownośc, wlaściwości teksturalne, wlaściwości reologiczne