Impact of bread making on fructan chain integrity and effect of fructan enriched breads on breath hydrogen, satiety, energy intake, PYY and ghrelin

Recently, there has been considerable interest in the satiety inducing properties of inulin type fructans (ITF) as a tool for weight management. As a staple food, breads provide an excellent vehicle for ITF supplementation however the integrity of the ITF chains and properties upon bread making need to be assessed. Breads enriched with 12% fructooligosaccharides (FOS) and 12% inulin were baked and the degree of polymerisation of fructans extracted from the breads were compared to those of pure compounds. An acute feeding study with a single blind cross-over design was conducted with 11 participants to investigate the effect of ITF enriched breads on breath hydrogen, self-reported satiety levels, active ghrelin, total PYY and energy intake. Size exclusion chromatography indicated that little or no depolymerisation of inulin occurred during bread making, however, there was evidence of modest FOS depolymerisation. Additionally, ITF enriched breads resulted in increased concentrations of exhaled hydrogen although statistical significance was reached only for the inulin enriched bread (p=0.001). There were no significant differences between bread types in reported satiety (p=0.129), plasma active ghrelin (p=0.684), plasma PYY (p=0.793) and energy intake (p=0.240). These preliminary results indicate that inulin enriched bread may be a suitable staple food to increase ITF intake. Longer intervention trials are required to assess the impact of inulin enriched breads on energy intake and body weight

Modulating process parameters to change physical properties of bigels for food applications

The effect of the process parameters involved in the production of bigels was investigated through the study of structural, mechanical and rheological properties. Four level (24) Central Composite Rotational Design (CCRD) configuration was applied in order to study the organogelator concentration, hydrocolloid concentration, organogel:hydrogel ratio and shear of mixing. Gellan gum and high oleic sunflower oil with glycerol monostearate were used to produce hydrogels and organogels, respectively. All formulations were water-in-oil systems with gel-like behavior. FTIR and XRD results showed that bigels were formed only by physical arrangement with no chemical interactions, but gellan gum decreased the crystallinity of the systems due to its amorphous character. However, hydrogel particles acted as an active filler, reinforcing the structure in comparison to pure gels. Also, the glycerol monostearate present in the organogel could self-assemble at the interface in order to interact with the aqueous phase, improving the interaction and affinity between the phases. Moreover, depending on the composition, systems could be softer or harder and present some frequency dependence. CCRD showed that all parameters evaluated changed with organogel:hydrogel ratio and organogel concentration. Shear of mixing was also significant for some parameters; however, hydrocolloid concentration did not exert a significant effect on the range studied. From PCA analysis it was possible to distinguish different groups, which means that some conditions produced bigels with similar characteristics. Thus, it is expected that these results will allow customizing and fine-tuning properties of structured two-phase systems for diverse applications, ranging from food to pharmaceutical and cosmetic industries.This study was also supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145- FEDER-006684) and BioTecNorte operation (NORTE-01-0145-FEDER000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. and of the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER027462)info:eu-repo/semantics/publishedVersio

Relating rheology and tribology of commercial dairy colloids to sensory perception

This study aims to investigate the relationship between rheological and tribological properties of commercial full fat and fat-free/ low fat versions of liquid and soft solid colloidal systems (milk, yoghurt, soft cream cheese) with their sensory properties. Oscillatory measurements (strain, frequency), flow curves and tribological measurements (lubricational behaviour using Stribeck analysis) were conducted. Oral condition was mimicked using artificial saliva at 37 ○C. Discrimination test was conducted by 63 untrained consumers, followed by a qualitative questionnaire. Consumers significantly discriminated the fat-free/low fat from the full fat versions (p0.05). Full fat and fat free yoghurts had similar yielding behaviour and elastic modulus (G'), even in simulated oral conditions. However, in case of soft cream cheese, the full fat version had a moderately higher G’ than the low fat counterpart. Even in presence of artificial saliva, there was slight but significant difference in viscoelasticity between the cream cheese variants depending on fat content (p0.05). Results suggest that sensory distinction between fat-free and full fat versions, particularly in semi-solid systems could be better predicted by lubrication data as compared to bulk rheology

Determining the effect of consuming fermented milk drinks on the incidence of constipation, diarrhoea and resistance to respiratory illness

Background. At present, there are many types of milk fermented drinks/beverages on the market that often contain added probiotic microflora. Numerous studies indicate that such products are frequently consumed by adolescents. Within this group, symptoms of respiratory illness feature prominently as well as various and frequent disorders of the gastro-intestinal system that give rise to either constipation or diarrhoea. Objectives. To determine the effect of consuming fermented milk drinks on the immune systems in teenagers aged 13-16 years through analysing their intakes in relation to how often respiratory illness, constipation and diarrhoea had occurred. Material and methods. A survey was performed on 150 middle-school pupils aged 13-16 years. Correlation coefficients were determined between the frequency of consuming fermented drinks with the incidences of respiratory disease, constipation or diarrhoea. Results. Most subjects declared that their state of health was satisfactory and that they regularly ate meals. Those consuming fermented milk drinks for over a year constituted 88%. It was found that 56% of all subjects drank such beverages at least once daily or several times a week. The decrease observed in consuming these drinks resulted in increasing problems of bowel evacuation ranging from 3% in those drinking daily to 26% that drank less than once monthly. The incidence of respiratory tract illness was seen to rise whenever fewer fermented milk beverages were consumed. Analogous findings were seen also in the incidence of diarrhoea. Subjects also considered that such drinks improved health and yoghurts were the most frequent type of these drinks consumed. Conclusions. Gastro-intestinal function may be enhanced by regular consumption of fermented milk drinks together with a decreased incidence of respiratory tract illness. However, the effect of how often such drinks are consumed on the aforementioned conditions remains unresolved.Wprowadzenie. Obecnie na rynku dostępnych jest szereg mlecznych napojów fermentowanych. Wiele z nich zawiera dodatkowo mikroflorę probiotyczną. Liczne badania pokazują, że młodzi ludzie chętnie spożywają tego typu napoje. Choroby dróg oddechowych są bardzo częste wśród młodzieży. Spośród dolegliwości układu pokarmowego nierzadkim problemem są zaparcia oraz biegunki. Cel badań. Celem pracy było ocena wpływu spożywania mlecznych napojów fermentowanych na odporność organizmu nastolatków w wieku 13-16 lat poprzez analizę zależności pomiędzy częstotliwością spożywania napojów fermentowanych a występowaniem biegunek, zaparć oraz chorób dróg oddechowych. Materiał i metoda. Analiz dokonywano na podstawie badań ankietowych przeprowadzonych wśród 150 uczniów gimnazjów w wieku 13-16 lat. W pracy wyliczano współczynniki korelacji pomiędzy spożywaniem mlecznych napojów fermentowanych a występowaniem biegunek, zaparć oraz chorób dróg oddechowych. Wyniki. Badana grupa młodzieży w większości deklarowała dobry stan zdrowia oraz regularnie się odżywiała. Udział osób deklarujących spożywanie mlecznych napojów fermentowanych dłużej niż rok wyniósł 88 %. 56 % badanych gimnazjalistów spożywało mleczne napoje fermentowane codziennie lub kilka razy w tygodniu. Spadek częstotliwości spożycia napojów fermentowanych wśród gimnazjalistów spowodował zwiększenie udziału procentowego osób deklarujących problemy z wypróżnianiem z 3 %, dla osób spożywających napoje fermentowane codziennie, do 26 % dla spożywających je rzadziej niż raz w miesiącu. Procentowy udział osób z często występującymi infekcjami dróg oddechowych wzrastał wraz ze spadkiem częstotliwości spożywania mlecznych napojów fermentowanych. Podobne zależności stwierdzono w przypadku występowania biegunek. Ankietowani sądzą, że mleczne napoje fermentowane mogą przyczyniać się do wzmocnienia organizmu. Respondenci spośród mlecznych napojów fermentowanych najczęściej wybierali jogurty. Wnioski. Regularne spożywanie mlecznych napojów fermentowanych może korzystnie wpływać na regulację pracy przewodu pokarmowego oraz rzadsze występowanie infekcji układu oddechowego. Nie wykazano jednoznacznego wpływu długości okresu spożywania mlecznych napojów fermentowanych na oceniane przypadłości

Textural and rheological properties of mixtures of inulin and milk fat stabilized by lecithin

Celem pracy było porównanie właściwości teksturalnych i reologicznych mieszanin otrzymanych na bazie tłuszczu 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, łączono z bezwodnym tłuszczem mlecznym o temp. 70 °C oraz lecytyną, a następnie homogenizowano. Sporządzone emulsje przechowywano przez 24 h w temp. 5 °C, a następnie oznaczano cechy reologiczne oraz teksturalne. Zarówno właściwości teksturalne (twardość, adhezyjność, kohezyjność, smarowność), jak i reologiczne (lepkość pozorna, moduł G’ i G”) powstałych emulsji w znacznym stopniu zależały od temperatury ogrzewania roztworu inuliny. Badane cechy mieszanin przygotowanych z zastosowaniem zawiesin inuliny ogrzewanej do temp. 65 °C charakteryzowały się znacznie mniejszym odchyleniem standardowym w stosunku do ogrzewanych do 100 °C. Prawdopodobną tego przyczyną była utrata zdolności do krystalizacji inuliny przez jej całkowite rozpuszczenie w 100 °C. Obecność t łuszczu mlecznego nie wpłynęła katalizująco na krystalizację inuliny. Niższa temperatura umożliwiła tworzenie jednorodnej emulsji. Stwierdzono, że wzrost stężenia inuliny oraz tłuszczu mlecznego spowodował wzrost twardości i zmniejszenie smarowności emulsji oraz że do wytworzenia emulsji o przewidywanych właściwościach teksturalnych i reologicznych konieczne jest stosowanie temperatur umożliwiających krystalizację inuliny.The objective of the research study was to compare the textural and rheological properties of emulsions produced on the basis of milk fat (15, 20 %), inulin (15, 18, 21, 24 %), and soya lecithin (2 %). The emulsions were prepared by making inulin suspensions in water, heating them to a temperature of 65 or 100 °C, and by mixing them with anhydrous milk fat of a temperature of 70 °C fat, and with lecithin. Next, the mixtures were homogenized and the finished emulsions were stored at a temperature of 5 °C for 24 hours. After that time, rheological and textural properties were determined. Both the textural (hardness, adhesiveness, cohesiveness, and spreadability) and rheological properties (apparent viscosity, G’ and G” moduli) of the emulsions produced depended, to a significant degree, on the temperature of heating the inulin suspension. The analyzed properties of the mixtures prepared with the use of inulin suspensions heated to a temperature of 65 °C were characterized by a significantly lower standard deviation compared to those heated to a temperature of 100 °C. A probable reason thereof was that inulin lost its crystallization ability when it was wholly dissolved at 100 °C. The presence of milk fat did not catalyse the crystallization of inulin. At a lower temperature, it was possible for a homogenous emulsion to form. It was confirmed that the increase in the concentration of inulin and milk fat caused the hardness of emulsion to increase and its spreadability to decrease. Furthermore, it was found that in order to obtain the emulsion showing foreseeable textural and rheological properties, it was necessary to apply temperatures allowing the crystallisation of inulin