Influence of carrot fibre powder addition on rheological, microstructure and sensory characteristics of stirred‐type yogurt

Abstract

The incorporation of 1% (E1) and 2% (E2) of the carrot fibre powder obtained from carrot discards to yogurts was studied. The effect of the fibre addition on the physicochemical parameters, waterholding capacity (WHC), microbial counts, rheological, microstructure and sensory characteristics of yogurts was studied in comparison with control yogurt without fibre addition (C). Titratable acidity, global composition and microbial counts showed a similar trend among yogurts. Fibre particles seemed to change the organisation of protein aggregates of the gel network. An open structure with bigger aggregates was observed in E1 and E2 yogurts, while the microstructure appeared more homogenous and without granules in C. However, carrot fibre increased the WHC of yogurt. All the yogurt samples exhibited shear-thinning behaviour and no differences were found in the rheological parameters, excepting for E2 that presented a decrease in apparent viscosity at 200 s -1 compared with C and E1 samples. Trained sensory panel (12 members) indicated an increase in brownish colour, strange flavour, grittiness and aftertaste and a decrease in overall appearance, odour, sweetness and creaminess in yogurts enriched in fibre. In order to mask these negative characteristics, E1 formulation was produced in the same way but strawberry flavour and colour were added. A consumer test (101 volunteers), purchase intention and a Check All That Apply (CATA) questionnaires were carried out. Flavoured and coloured E1 yogurt was pleasant for consumers, since 93% of the consumers selected positive degrees of acceptability and 68% of them manifested that they are willing to consume the product. Therefore, the addition of carrot fibre powder in yogurts could be an alternative to incorporate dietary fibres into dairy foods.

Fortification of milk-based yogurt with protein hydrolysates from brewers' spent grain: Evaluation on microstructural properties, lactic acid bacteria profile, lactic acid forming capability and its physical behavior

“…This phenomenon demonstrates that BSGPs resulted in the yogurt having increased gel formation, which could be beneficial for the textural properties as well as for the consistency and for reducing syneresis. Different shear stress trends in yogurt have been reported previously and were found to be dependent on the ingredients that had been added as well as the treatments ( Azari-Anpar et al, 2021 ; Körzendörfer et al, 2019 ; Vénica et al, 2020 ), which were shown to be related to flow behavior-related properties, microstructural properties, and syneresis.…”

“…The shear stress of the YC increased due to the increase in the shear rate, while the yogurt prepared with the YP had the most stable shear stress. Shear stress represents the energy required to damage the structure of the yogurt matrix ( Vénica et al, 2020 ), thus showing the strength of the matrix. Because of this, the addition of BSGP-C might have induced gel formation faster than BSGP-P and BSGP-PF.…”

Tremella fuciformis polysaccharides as a fat substitute on the rheological, texture and sensory attributes of low-fat yogurt

“…The evaluation of yogurt samples included the following sensory attributes: appearance, color, texture, acidity, taste and overall acceptability. The scale used is the 9-point Hedonic scale, where 1 means dislike extremely, 5 means neither dislike nor like, and 9 means like extremely ( Vénica et al, 2019 ).…”

Impact of sea buckthorn berries (Hippophae rhamnoides) on yoghurt biological value and quality

“…Studies published in the works of various scientists claim that during the fermentation process, lactic acid produced by bacterial cultures causes a reduction in pH, from an initial value of about 6.0 -6.5 to a final pH of 4.0 -4.6 (Mediza Romero et al, 2021;Vénica et al, 2020). As soon as the pH of the product has reached the value within the limits of 4.0-4.6, the fermentation process is stopped by placing the yoghurt in the cold.…”