Effect of Resistant Cassava Starch on Quality Parameters and Sensory Attributes of Yoghurt

Effect of retrograded starch with different amylose content on the rheological properties of stored yogurt

Resistant starch (RS) promotes health benefits; however, when added to foods, it could change the rheological properties. The effect of adding different concentrations (2.5, 5, 7.5, and 10%) of retrograded corn starch with 27% (RNS) or 70% (RHS) amylose content on the properties of yogurt was evaluated through measurements of flow behavior and gel structure. Syneresis and resistant starch content were also assessed. Results were analyzed using multiple regression to describe the effect of starch concentration and storage time on the properties of yogurt added with RNS or RHS. Syneresis was reduced, RNS reinforced the structure increasing the water absorption capacity and the consistency index; meanwhile, RHS provided a yogurt containing up to 10 g of RS in 100 g of sample, allowing obtaining a functional dairy product. Creep-recovery test showed that adding RNS or RHS favored the matrix conformation, and the yogurt samples were able to recover. The final product behaved like a solid material with a firmer and more stable gel structure, resulting in a strengthened gel without weakening the yogurt structure, showing a characteristic like Greek-style or stirred yogurt depending on the type and concentration of retrograded starch.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-023-05735-x.

A comprehensive review on yogurt syneresis: effect of processing conditions and added additives

Yogurt, produced by the lactic fermentation of milk base, is an important dairy product worldwide. One of the essential sensory properties of yogurt is the texture, and some textural defects such as weak gel firmness and syneresis likely occur in various types of yogurts, affecting consumer acceptance. In this regard, various strategies such as enrichment of milk-based with different additives and ingredients such as protein-based components (skimmed milk powder (SMP), whey protein-based powders (WP), casein-based powders (CP), and suitable stabilizers, as well as modification of processing conditions (homogenization, fermentation, and cooling), can be applied in order to reduce syneresis. The most effective proteins and stabilizers in syneresis reduction are CP and gelatin, respectively. Furthermore, yogurt's water holding capacity and syneresis can be affected by the type of starter cultures, the protolithic activity, production of extracellular polysaccharides, and inoculation rate. Moreover, optimizing the heat treatment process (85 °C/30 min and 95 °C/5 min), homogenization (single or dual-stage), incubation temperature (around 40 °C), and two-step cooling process can decrease yogurt syneresis. This review is aimed to investigate the effect of fortification of the milk base with various additives and optimization of process conditions on improving texture and preventing syneresis in yogurt.

Effect of adding high concentrations of retrograded starch with different amylose content on the physicochemical properties and sensory attributes of Greek-style yogurt

It is well known that using retrograded starches confers many technological advantages, as well as health benefits when consumed in adequate doses; however, these properties are closely related to the type of starch and/or the treatment applied, therefore, it is of interest to add retrograded starch to popular products such as Greek yogurt. The aim of this work was to investigate the effect of adding two types of retrograded corn starch with different amylose content to a non-strained type of Greek-style yogurt. Retrograded starch from starch containing 27 % (RNS) or 70 % (RHS) amylose was added to yogurt at 0, 10, 12.5, or 15 g/100 g before storage at 4 °C for 14 d. The resistant starch (RS) content, pH, syneresis, flow behavior index, and consistency index, were measured every week. A sensory test was carried out in yogurt added with 12.5 g/100 g of retrograded starches to evaluate acceptability. Adding retrograded starch significantly reduced syneresis while increasing the consistency, firmness, and resistant starch content of the yogurt. No significant differences in general acceptance were observed in samples added with RNS when compared to control. Although a significant difference was observed after adding RHS, the acceptance of the product is still convenient. Adding a high concentration of retrograded starch could help to ensure doses enough for a prebiotic effect of RS with concentrations of 1.74 ± 0.37 to 2.32 ± 0.09 g/100 g and from 3.5 ± 0.08 to 4.21 ± 0.08 g/100 g when RNS or RHS is added while maintaining the quality characteristics of Greek-style yogurt during storage without compromising the acceptability.

Effect of Two Combined Functional Additives on Yoghurt Properties

The aim of the research was the analysis of yoghurts enriched with blue honeysuckle berries dry polyphenolic extract and new preparation of resistant starch. The additives were introduced individually at concentration 0.1% (w/v) and in mixture at final concentration of 0.1 and 0.2% of both components. Yogurt microflora, pH, and its physicochemical and antioxidant properties were examined over 14 days of storage under refrigerated conditions. Studies showed that both substances can be successfully used in yoghurt production. Yoghurt microflora es. S. thermophilus and Lb. delbrueckii subsp. bulgaricus counts appeared to be higher in samples supplemented with these additives comparing to control yoghurt by 3-8%. More stimulating effect on their growth, especially on S. thermophilus, revealed resistant starch. Addition of this polysaccharide improved also the rheological properties of yogurts, which showed higher viscosity than samples produced without it. Addition of honeysuckle berries preparation significantly influenced the yogurts' color, giving them deep purple color, and their antioxidant potential. During storage, contents of anthocyanin and iridoid compounds were decreasing, but antioxidant activity in the products remained stable.

Technological Properties of Acetylated Pigeon Pea Starch and Its Stabilized Set-Type Yoghurt

The behaviour of graded acetylated pigeon pea starch during heat processing was evaluated in addition to the corresponding effect of their incorporation at 1.5% (w/v) as a stabilizer in set-type yoghurt. Acetylated starch possessed higher solubility and swelling power than native starch under the temperature regimes considered. Addition of acetylated pigeon pea starch as a stabilizer in yoghurt had positive influence on the water holding capacity (7.7% to 10.4% compared to 13.3% in yoghurt stabilized with native pigeon pea starch) and whey syneresis (approximately 15%, 12%, and 8% increase observed in yoghurt with acetylated pea starch compared to 47% in yoghurt with native pea starch stabilizer) at the end of a 28-day cold storage period. In addition, pea starch-stabilized yoghurt possessed an enhanced sensory attribute (firmness), and compared favourably with gelatin-stabilized yoghurt in terms of overall acceptability. Thus, acetylated pigeon pea starch exhibited improved physicochemical properties and showed usefulness as a stabilizer in yoghurt because it enhanced the physicochemical, storability, and sensorial quality, while improving the body and texture of the product.

Nonfat Set Yogurt: Effect of Okra Gum and Various Starches on the Rheological, Sensory, and Storage Qualities and Wheying-Off

This work was intended to determine the effect of okra gum in combination with various starches on the flow and sensory properties of nonfat set yogurt. The selected starches include potato (PS), sweet potato (SPS), corn (CO), chickpea (CP), and Turkish beans (TB). The control is the yogurt prepared with okra gum only. Samples were analyzed under optimum conditions for their shear viscosity, viscoelasticity, texture, wheying-off, and sensory evaluation. Tests were performed at the beginning of the cold storage and after 7 or 15 days. By adding 1.0% starch, significant (p<0.05) reduction in wheying-off and firmer yogurt was obtained. Variations in the properties of yogurt were obvious and can be attributed to starch origin and amylose content. Therefore, the qualities of yogurts with tuber starches (PS and SPS) were different compared to corn or legume starches (CP and TB). The effect of the starches on yogurt properties changed over storage time, where some starches performed better only at the beginning of the storage period, and steady pH was maintained throughout the storage time. Wheying-off was significantly reduced irrespective of the origin of the starch. Sensory evaluation showed preference for yogurts prepared with starch compared to the control, regardless of starch type. Nonetheless, CP was preferred over other starches with respect to wheying-off, power law parameters, and overall acceptability.

Effect of Different Starches on the Rheological, Sensory and Storage Attributes of Non-fat Set Yogurt

This study was conducted to investigate the effect of various native starches on the rheological and textural properties of non-fat set yogurt. The yogurt samples were prepared while using five types of starches (potato, sweet potato, corn, chickpea, and Turkish beans). The physical properties of the prepared yogurt were analyzed while using shear viscosity, viscoelasticity, and texture analysis. The tests were performed after 0, 7, and 15 days storage. The effect of these starches on the yogurt viscoelastic properties, texture, syneresis, and sensory evaluation were determined under optimum conditions. The results showed that adding 1% starch could significantly (p < 0.05) reduce syneresis and improve yogurt firmness. Starches exhibited different effect on the overall quality of the yogurt due to their origin and amylose content. Regardless of the number of storage period duration, all of the samples, including the control behaved as pseudoplastic materials (n < 1) with various levels of pseudoplasticity. Yogurts with corn and tuber starches had the highest consistency coefficient (k), which indicated higher viscosity. The yogurt sample with chickpea starch exhibited the highest G´, making the gel more solid like. Therefore, the influence of tuber starches (potato and sweet potato) on G´ was different when compared to corn or legume starches. The behavior of the starches changed with storage time, where some starches performed better only at the beginning of the storage period duration. Wheying-off was significantly reduced, regardless of starch type. The pH of the yogurt remained unchanged through storage. Sensory evaluation showed a preference for starch-containing samples as compared to the control, regardless of the starch type. The variation in yogurt quality as a function of starch type could be attributed to the starch granule structure, gelatinization mechanism, or amylose content.