Impact of native and chemically modified starches addition as fat replacers in the viscoelasticity of reduced-fat stirred yogurt

Utilization of ripe coconut water in the development of probiotic gelatin

Background

Desserts with vegetable ingredients are a constantly expanding global market due to the search for alternatives to cow's milk. Fermentation of these matrices by lactic acid bacteria can add greater functionality to the product, improving its nutritional, sensory, and food safety characteristics, as well as creating bioactive components with beneficial effects on health. Concern for health and well-being has aroused interest in byproducts of the industry that have functional properties for the body, such as mature coconut water, a normally discarded residue that is rich in nutrients. This study aimed to develop a probiotic gelatin based on pulp and water from mature coconuts and evaluate the physicochemical characteristics, viability of the Lacticaseibacillus rhamnosus LR32 strain in the medium, as well as the texture properties of the product.

Methods

After collection and cleaning, the physicochemical characterization, mineral analysis, analysis of the total phenolic content and antioxidant activity of mature coconut water were carried out, as well as the centesimal composition of its pulp. Afterwards, the gelling was developed with the addition of modified corn starch, gelatin, sucrose, and probiotic culture, being subjected to acidity analysis, texture profile and cell count, on the first day and every 7 days during 21 days of storage, under refrigeration at 5 °C. An analysis of the centesimal composition was also carried out.

Results

The main minerals in coconut water were potassium (1,932.57 mg L-1), sodium (19.57 mg L-1), magnesium (85.13 mg L-1) calcium (279.93 mg L-1) and phosphorus (11.17 mg L- 1), while the pulp had potassium (35.96 g kg-1), sodium (0.97 g kg-1), magnesium (2.18 g kg-1), 37 calcium (1.64 g kg-1), and phosphorus (3.32 g kg-1). The phenolic content of the water and pulp was 5.72 and 9.77 mg gallic acid equivalent (GAE) 100 g-1, respectively, and the antioxidant capacity was 1.67 and 0.98 39 g of 2, 2-diphenyl-1-picrylhydrazyl (DPPH) mg-1, respectively. The coconut pulp had 2.81 g 100 g-1of protein, 1.11 g 100 g-1 of 40 ash, 53% moisture, and 5.81 g 100 g-1 of carbohydrates. The gelatin produced during the storage period presented firmness parameters ranging from 145.82 to 206.81 grams-force (gf), adhesiveness from 692.85 to 1,028.63 gf sec, cohesiveness from 0.604 to 0.473, elasticity from 0.901 to 0.881, gumminess from 86.27 to 97.87 gf, and chewiness from 77.72 to 91.98 gf. Regarding the viability of the probiotic microorganism, the dessert had 7.49 log CFU g-1 that remained viable during the 21-day storage, reaching 8.51 CFU g-1. Acidity ranged from 0.15 to 0.64 g of lactic acid 100 g-1. The centesimal composition of the product showed 4.88 g 100 g-1 of protein, 0.54 g 100 g-1 of ash, 85.21% moisture, and 5.37g 100 g-1 of carbohydrates. The development of the gelatin made it possible to obtain a differentiated product, contributing to diversification in the food sector, providing a viable alternative for maintaining consumer health and reducing costs compared to desserts already available on the market.

Fortified chocolate mousse with powder and extract from Moringa oleifera leaves for nutritional value improvement

This study focuses on the characterisation and incorporation of Moringa oleifera leaf powder (MOP) from Luanda (Angola) and its extract (MOE) in fortified chocolate mousse. Dark green (DG) leaves presented superior nutritional values compared to other leaves. DG contained a higher concentration of mineral salts (10 ± 1 mg/100 g of dry leaves), phenolic compounds (267 ± 4 mg GAE/g), vitamins (1.9 ± 0.2 mg/g of dry extract) and strong antioxidant capacity (IC50, 115 ± 8 µg/mL). Therefore, DG leaves were used to fortify the chocolate mousse. The leaves were prepared in three samples: control, 2 % MOP (w/w) and 2 % MOE (v/v). Textural and rheological analysis of chocolate mousse samples revealed a pseudoplastic profile for all samples, with decreased texture attributes and viscosity due to the incorporation. The sensory evaluation demonstrated that MOP and MOE samples presented 93 % and 88 % resemblance to the original product regarding general acceptance, respectively.

Effects of water-soluble and water-insoluble α-glucans produced in situ by Leuconostoc citreum SH12 on physicochemical properties of fermented soymilk and their structural analysis

This study investigated the effect of in situ produced water-soluble α-glucan (LcWSG) and water-insoluble α-glucan (LcWIG) from Leuconostoc citreum SH12 on the physicochemical properties of fermented soymilk. α-Glucans produced by Leuc. citreum SH12 improved water-holding capacity, viscosity, viscoelasticity and texture of fermented soymilk. Gtf1365 and Gtf836 of the five putative glucansucrases were responsible for synthesizing LcWSG and LcWIG during soymilk fermentation, respectively. Co-fermentation of soymilk with Gtf1365 and Gtf836 and non-exopolysaccharide-producing Lactiplantibacillus plantarum D1031 indicated that LcWSG effectively hindered the whey separation of fermented soymilk by increasing viscosity, while LcWIG improved hardness, springiness and accelerated protein coagulation. Fermented soymilk gel formation was mainly based on hydrogen bonding and hydrophobic interactions, which were promoted by both LcWSG and LcWIG. LcWIG has a greater effect on α-helix to β-sheet translation in fermented soymilk, causing more rapid protein aggregation and thicker cross-linked gel network. Structure-based exploration of LcWSG and LcWIG from Leuc. citreum SH12 revealed their distinct roles in the physicochemical properties of fermented soymilk due to their different ratio of α-1,6 and α-1,3 glucosidic linkages and various side chain length. This study may guide the application of the water-soluble and water-insoluble α-glucans in fermented plant protein foods for their quality improvement.

Effects of hydrocolloids and oleogel on techno-functional properties of dairy foods

This paper aims to overview the influence of different gels that including hydrocolloids and oleogel on techno-functional changes of dairy foods. The hydrocolloids are widely added to dairy products as stabilizers, emulsifiers, and gelling agents to enhance their texture, or improve sensory properties to meet consumer needs; and the newly developed oleogel, which despite less discussed in dairy foods, this article lists its application in different dairy products. The properties of different hydrocolloids were explained in detail, meanwhile, some common hydrocolloids such as pectin, sodium alginate, carrageenan along with the interaction between gel and proteins on techno-functional properties of dairy products were mainly discussed. What's more, the composition of oleogel and its influence on dairy foods were briefly summarized. The key issues have been revealed that the use of both hydrocolloids and oleogel has great potential to be the future trend to improve the quality of dairy foods effectively.

Heat-moisture-treated rice starches with different amylose and moisture contents as stabilizers for nonfat yogurt

Food producers are interested in enhancing native starch properties without chemical modifications. Here, rice starches were physically modified via heat-moisture treatment (HMT) using different amylose (high, medium, low, and waxy) and moisture (15 %, 20 %, 25 %, and 30 %) contents. Hydration properties and pasting viscosities differed for different amylose and moisture contents. The HMT starch with high amylose content and 15 % moisture (High_HMT15) exhibited the highest final viscosity (6.16 Pa.s), and 31.7 % and 35.1 % increased amount of resistant starch compared to native starch in the granule and paste states, respectively. Hence, High_HMT15 was used as a stabilizer for nonfat yogurt. The nonfat yogurt prepared with 1.0 % High_HMT15 as the stabilizer exhibited 37.3 % reduced whey separation, 2.8 times increased viscosity, a high total solids content, and acceptable sensory properties compared to the nonfat yogurt without starch. These HMT starches can replace chemically modified starches derived from other grains in various food applications.

The colloid and interface strategies to inhibit lipid digestion for designing low-calorie food

Although fat is one of the indispensable components of food flavor, excessive fat consumption could cause obesity, metabolism syndromes and an imbalance in the intestinal flora. In the pursuit of a healthy diet, designing fat reducing foods by inhibiting lipid digestion and calorie intake is a promising strategy. Altering the gastric emptying rates of lipids as well as acting on the lipase by suppressing the enzymatic activity or limiting lipase diffusion via interfacial modulation can effectively decrease lipolysis rates. In this review, we provide a comprehensive overview of colloid-based strategies that can be employed to retard lipid hydrolysis, including pancreatic lipase inhibitors, emulsion-based interfacial modulation and fat substitutes. Plants-/microorganisms-derived lipase inhibitors bind to catalytic active sites and change the enzymatic conformation to inhibit lipase activity. Introducing oil-in-water Pickering emulsions into the food can effectively delay lipolysis via steric hindrance of interfacial particulates. Regulating stability and physical states of emulsions can also affect the rate of hydrolysis by altering the active hydrolysis surface. 3D network structure assembled by fat substitutes with high viscosity can not only slow down the peristole and obstruct the diffusion of lipase to the oil droplets but also impede the transportation of lipolysis products to epithelial cells for adsorption. Their applications in low-calorie bakery, dairy and meat products were also discussed, emphasizing fat intake reduction, structure and flavor retention and potential health benefits. However, further application of these strategies in large-scale food production still requires more optimization on cost and lipid reducing effects. This review provides a comprehensive review on colloidal approaches, design, principles and applications of fat reducing strategies to meet the growing demand for healthier diet and offer practical insights for the low-calorie food industry.

Morphological, textural analysis and freeze-thaw stability of starches from legume grow in Cameroon

Starches from some legume grown in Cameroon were evaluated for their granule structure and size, turbidity, firmness and gel strength, thermal and freeze-thaw properties. Amylose contents were in the range of 26.21%-44.85%. Morphological analysis of the starch granules showed bimodal distribution, multiple sizes and shapes from small spherical to the bigger kidney shape. Significant differences were observed among starch in light transmittance, firmness and gel strength. The thermal parameters of starches were evaluated using differential scanning calorimeter and significant differences were observed. The peak gelatinisation temperature was positively correlated to starch granule size but the amylose content showed no evidence of their impact on legume starch properties studied. The data reported can be useful to facilitate the selection of variety of legume and conditions closer to the desired application.

Preparation of fat substitute based on maize starch hydrolysates and application in reduced-fat acidified milk gel

Reduced-fat food has become a popular choice among contemporary consumers. This study aims to develop a starch-based fat substitute and incorporate it into reduced-fat milk gel acidified with glucono-δ-lactone (GDL) to achieve similar rheological properties as a full-fat gel. The gel properties of the fat substitute were assessed. The study examined the rheological properties, syneresis, textural properties and microstructure of acidified milk gels while also monitoring acidification process. Starch hydrolysates with low dextrose equivalent (DE) (<5.1 %) can serve as an effective fat substitute due to their excellent gelling properties The rheological and textural properties of the reduced-fat acidified milk gel with DE at 3.1 % of starch hydrolysate and 30 % fat substitution are similar to those of the full-fat milk gel. The syneresis and confocal laser scanning microscopy (CLSM) results indicated that the microstructure of the reduced-fat acidified milk gel was similar to the full-fat version. Moreover, the sensory properties of the reduced-fat acidified milk gel were acceptable when the DE was 3.1 %, and 30 % fat was replaced. In our study, we utilized hydrolyzed starch to produce reduced-fat acidified milk gels, which could potentially be used in the development of reduced-fat yogurt formulations.

Emulsion Gels Formed by Electrostatic Interaction of Gelatine and Modified Corn Starch via pH Adjustments: Potential Fat Replacers in Meat Products

The application of emulsion gels as animal fat replacers in meat products has been focused on due to their unique physicochemical properties. The electrostatic interaction between proteins and polysaccharides could influence emulsion gel stability. This study aimed to evaluate the physicochemical properties of emulsion gels using starch and gelatin as stabilizers, promoting electrostatic attraction via pH adjustment. Three systems were studied: emulsion gel A (EGA) and emulsion gel B (EGB), which have positive and negative net charges that promote electrostatic interaction, and emulsion gel C (EGC), whose charge equals the isoelectric point and does not promote electrostatic interactions. There was no significant difference in proximate analysis, syneresis and thermal stability between samples, while EGA and EGB had higher pH values than EGC. The lightness (L*) value was higher in EGA and EGB, while the yellowness (b*) value was the highest in EGC. The smaller particle size (p < 0.05) in EGA and EGB also resulted in higher gel strength, hardness and oxidative stability. Microscopic images showed that EGA and EGB had a more uniform matrix structure. X-ray diffraction demonstrated that all the emulsion gels crystallized in a β′ polymorph form. Differential scanning calorimetry (DSC) revealed a single characteristic peak was detected in both the melting and cooling curves for all the emulsion gels, which indicated that the fat exists in a single polymorphic state. All emulsion gels presented a high amount of unsaturated fatty acids and reduced saturated fat by up to 11%. Therefore, the emulsion gels (EGA and EGB) that favored the electrostatic protein-polysaccharide interactions are suitable to be used as fat replacers in meat products.

Impact of the droplet size of canola oil-in-water emulsions on the rheology and sensory acceptability of reduced-milk fat stirred yogurt

A coarse canola oil-in-water (O/W) emulsion (dispersed mass fraction 0.1) was prepared by adding oil to whey protein hydrolysate (WPH)-citric pectin (CP) soluble complex (1% total biopolymer weight; WPH to CP mass ratio 6:1; pH 4.25) aqueous phase using a high shear homogenizer (4000 rpm, 2 min). The coarse O/W emulsion was further homogenized to obtain emulsions (Ex) with different mean droplet sizes (4000, 3000, 120 and 60 nm). A full-fat yogurt (YC; 26 ± 0.3 g milk fat L-1) was prepared from reconstituted whole milk powder (WMP, 3% milk fat) and skim milk powder (SMP, 0.01% milk fat). Reduced-milk fat yogurt (YEx 13 ± 0.3 g milk fat L-1) variations were prepared from WMP + SMP + Ex, where Ex substituted 50% of the milk-fat contained in YC. The viscosity and viscoelastic moduli were lower for YEx than for YC; the effect was more pronounced for E60 and E120. Aroma was non-significantly different between YC and YEx. A multivariate analysis showed that YEx overall acceptability was linked to taste and after taste attributes and to the viscosity perceived in mouth. The loss modulus showed anti-correlation directionality with the overall acceptance. The smaller mean droplet sized YEx exhibited the highest overall acceptability.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-022-05573-3.

Bacterial redox response factors in the management of environmental oxidative stress

Bacteria evolved to survive in the available environmental chemosphere via several cellular mechanisms. A rich pool of antioxidants and stress regulators plays a significant role in the survival of bacteria in unfavorable environmental conditions. Most of the microbes exhibit resistant phenomena in toxic environment niches. Naturally, bacteria possess efficient thioredoxin reductase, glutaredoxin, and peroxiredoxin redox systems to handle environmental oxidative stress. Further, an array of transcriptional regulators senses the oxidative stress conditions. Transcription regulators, such as OxyR, SoxRS, PerR, UspA, SsrB, MarA, OhrR, SarZ, etc., sense and transduce bacterial oxidative stress responses. The redox-sensitive transcription regulators continuously recycle the utilized antioxidant enzymes during oxidative stress. These regulators promote the expression of antioxidant enzymes such as superoxide dismutase, catalase, and peroxides that overcome oxidative insults. Therefore, the transcriptional regulations maintain steady-state activities of antioxidant enzymes representing the resistance against host cell/environmental oxidative insults. Further, the redox system provides reducing equivalents to synthesize biomolecules, thereby contributing to cellular repair mechanisms. The inactive transcriptional regulators in the undisturbed cells are activated by oxidative stress. The oxidized transcriptional regulators modulate the expression of antioxidant and cellular repair enzymes to survive in extreme environmental conditions. Therefore, targeting these antioxidant systems and response regulators could alter cellular redox homeostasis. This review presents the mechanisms of different redox systems that favor bacterial survival in extreme environmental oxidative stress conditions.

Development of low glycemic index instant Phirni (pudding) mix-its visco-thermal, morphological and rheological characterization

High amylose rice (HAR) and carboxymethyl cellulose (CMC) are the preferred choices for enhancement of resistant starch content and lowering of glycemic index in dairy desserts. The effects of different levels of skimmed milk powder (SMP): HAR flour (45:55 to 75:25) and CMC (0.1 to 1%) were investigated on physical characteristics of dry-mix and on texture profile parameters, resistant starch (RS), predicted glycemic index (pGI), glycemic load (GL) and overall acceptability of phirni (a traditional milk pudding). Design expert predicted SMP (70): HAR (30) and CMC (0.8%) as optimum levels for reducing the pGI and maximizing the RS content and other quality characteristics in phirni. RS content of phirni (4.38%) prepared from optimized dry-mix (ODM) was higher while pGI (48.12) and GL (7.50) were lower as compared to phirni prepared from market dry-mix (MDM). The visco-thermal properties of ODM and MDM also showed significant variations. Storage modulus (Gʹ) and loss modulus (Gʹʹ) indicated that ODM phirni was less solid than MDM phirni. Scanning electron micrographs showed fused structures in ODM, while coarse sheet like structures were observed across the surface of MDM. Thus, ODM can be a promising substitute for the available milk desserts for diabetic patients.

Tapioca starch and skim milk support probiotic efficacy of Lactiplantibacillus plantarum post-fermentation medium against pathogens and cancer cells

The production of functional foods containing prebiotic ingredients is an area of particular interest and a very promising market with the potential to dominate the food industry. This study aims to explore the potential of starch-based prebiotic tapioca and skim milk, as low-cost and easily accessible food sources and as natural and "clean label" food ingredients on the probiotic activities of Lactiplantibacillus plantarum (formerly Lactobacillus plantarum). The results show that concomitant use of the modified tapioca starch and skim milk promotes the antibacterial and anti-cancer properties of L. plantarum post-fermentation media pointing out how the functionality of probiotic products can be regulated by growth supplements.

Physicochemical properties, sensory characteristics, and antioxidant activity of the goat milk yogurt probiotic Pediococcus acidilactici BK01 on the addition of red ginger (Zingiber officinale var. rubrum rhizoma)

Background and Aim:

Yogurt contains beneficial probiotics. Addition of red ginger to yogurt as an antioxidant source becomes a way to improve the flavor and functional properties of yogurt. This study aimed to examine yogurt processing and the effect of adding red ginger (Zingiber officinale var. rubrum rhizoma), as an antioxidant source, on Pediococcus acidilactici BK01. It sought to observe the physicochemical and sensory qualities during storage (4°C).

Materials and Methods:

Goat milk was obtained from local farmers in Lubuk Minturun, Padang, West Sumatra, Indonesia. The yogurt was divided into two factors. Factor A was supplemented with red ginger in various concentrations: A (0% – as control), B (1%), C (2%), and D (3%). On the other hand, Factor B was subjected to variations in storage time: A (1 day), B (15 days), and C (30 days). Each treatment was conducted in triplicate. Physicochemical properties (pH, titratable acidity [TTA], and proximate analysis), sensory characteristics, and antioxidant activity (2,2-diphenyl-1-picrylhydrazyl radical scavenging capacity) were measured using the standard tests. The data were analyzed through analyzing multivariate (analysis of variance) supported by Duncan’s multiple range test.

Results:

The addition of red ginger juice increased the antioxidant activity, TTA, and water holding capacity (WHC) (p<0.05), while syneresis was significantly decreased; however, it had no effect on the total lactic acid bacteria. At the end of this research (day 30), the yogurt was still suitable for consumption, with the following composition: Antioxidant activity 48.39%, pH 4.3, TTA 1.716, water content 80%, protein 3%, fat 3%, syneresis 28%, WHC 63%, and total lactic acid bacteria 89×10⁸ colony-forming units/mL. Furthermore, yogurt supplemented with red ginger changed its color into red blush.

Conclusion:

Yogurt red ginger juice is recommended as a functional drink, as it contains probiotics P. acidilactici BK01 and antioxidants to support human health. The addition of up to 3% ginger juice and a storage period of 30 days are still favored by the panelists and meet the quality standard of yogurt. We have not conducted the study on active compounds so, further research could be conducted on the components of the active compounds found in red ginger yogurt.

Nutritional and Volatile Characterisation of Milk Inoculated with Thermo-Tolerant Lactobacillus bulgaricus through Adaptive Laboratory Evolution

In this study, thermo-tolerant strain of Lactobacillus bulgaricus (L. bulgaricus) was developed using gradual increase in temperature to induce Adaptive Laboratory Evolution (ALE). Viable colony count of 1.87 ± 0.98 log cfu/mL was achieved at 52 °C, using MRS agar supplemented with 2% lactose. Changes in bacteria morphology were discovered, from rod (control) to filament (52 °C) to cocci after frozen storage (−80 °C). When milk was inoculated with thermo-tolerant L. bulgaricus, lactic acid production was absent, leaving pH at 6.84 ± 0.13. This has caused weakening of the protein network, resulting in high whey separation and lower water-holding capacity (37.1 ± 0.35%) compared to the control (98.10 ± 0.60%). Significantly higher proteolytic activity was observed through free amino acids analysis by LC-MS. Arginine and methionine (237.24 ± 5.94 and 98.83 ± 1.78 µg/100 g, respectively) were found to be 115- and 275-fold higher than the control, contributing to changing the aroma similar to cheese. Further volatile analysis through SPME-GC-MS has confirmed significant increase in cheese-aroma volatiles compared to the control, with increase in diacetyl formation. Further work on DNA profiling, metabolomics and peptidomics will help to answer mechanisms behind the observed changes made in the study.

GABA enhancement by simple carbohydrates in yoghurt fermented using novel, self-cloned Lactobacillus plantarum Taj-Apis362 and metabolomics profiling

This study aimed to enhance natural gamma aminobutyric acid (GABA) production in yoghurt by the addition of simple sugars and commercial prebiotics without the need for pyridoxal 5′-phosphate (PLP) cofactor. The simple sugars induced more GABA production (42.83–58.56 mg/100 g) compared to the prebiotics (34.19–40.51 mg/100 g), with glucose promoting the most GABA production in yoghurt (58.56 mg/100 g) surpassing the control sample with added PLP (48.01 mg/100 g). The yoghurt prepared with glucose also had the highest probiotic count (9.31 log CFU/g). Simulated gastrointestinal digestion of this GABA-rich yoghurt showed a non-significant reduction in GABA content and probiotic viability, demonstrating the resistance towards a highly acidic environment (pH 1.2). Refrigerated storage up to 28 days improved GABA production (83.65 mg/100 g) compared to fresh GABA-rich yoghurt prepared on day 1. In conclusion, the addition of glucose successfully mitigates the over-use of glutamate and omits the use of PLP for increased production of GABA in yoghurt, offering an economical approach to produce a probiotic-rich dairy food with potential anti-hypertensive effects.

Physico-Chemical and Antioxidant Properties of Skimmed Varenets (Slavic Baked Milk Yogurt) Mixed with Enzyme-Modified Potato Starches

The present studies have examined the effect of potato starches treated with amylase B.licheformis (Bl) (laboratory sample) or Amylosubtilin® (AM) (Berdsk Factory of Biological Preparations (now: Sibbiofarm), Russia) in different concentrations on the quality of Slavic skim milk drink Varenets made from baked milk. The baked milk is milk heated to 98 °C for 3 hours, it has a sweet aroma and taste and creamy hue. The presence of enzyme-modified potato starches (Bl or AM) has been found to promote the activation of lactic acid fermentation, the accumulation of exopolysaccharides, and such stabilized products have a higher viscosity, a lower percentage of syneresis compared to the control sample. The antioxidant capacity of the Varents samples after fermentation was evaluated by two assays: analysis of radical capture activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH •); and the ability to restore Fe + 3 (Iron Reduction Antioxidant Ability Assay, FRAP). All Varentz samples showed different values for DPPH, FRAP assays depending on the starches used. The Introduction of pre-fermented starches into defatted jam promotes formation of enhanced antioxidant properties of milk product. The use of starches modified with enzymes improves sensory characteristics, in particular, as a fat imitator, formsfull taste of the drink.

Effect of yam (Dioscorea spp.) starch on the physicochemical, rheological, and sensory properties of yogurt

This study investigated the effect of the addition of starch from “hawthorn” yam (Dioscorea rotundata) and “creole” yam (Dioscorea alata) at different concentrations (0.1%, 0.3%, and 0.5% w/w) on the physicochemical and sensory properties of stirred-type yogurt. Pectin (0.3% w/w) was used as a reference stabilizer. Yogurt with yam starch presented 13.38% less syneresis than yogurts with pectin. At the sensory level, the most accepted treatment was yogurt with “creole” yam starch at 0.1% w/w. During 21 days of storage, yogurt with yam starch (“creole” and “hawthorn”) at 0.1% w/w showed a decrease in syneresis between 7% and 8%, while in those with pectin, syneresis remained practically constant in this period. Yogurt with yam starch was characterized as a pseudoplastic fluid, with a lactic acid bacterial count according to NTC 805. Yam starch can be used as stabilizer because it improves the physicochemical, sensory, and rheological characteristics of stirred-type yogurt. Especially the “creole” yam starch (0.1% w/w), which presents the best preference by consumers.

Physicochemical properties, texture, and probiotic survivability of oat-based yogurt using aquafaba as a gelling agent

Despite high consumer demands, the manufacture of nondairy yogurt from oat milk is currently hindered due to the lack of consistency and texture. An oat-based yogurt was developed using oat milk and probiotics (Streptococcus thermophilus and Lactobacillus bulgaricus) with aquafaba (AF) and vegetable oil (VO) as added ingredients. Physicochemical analyses and viability of probiotics were investigated after yogurt formation and for 3 weeks under refrigerated storage. Results showed that adding AF decreased syneresis and increased water holding capacity during storage. Both AF and VO had a beneficial effect on hardness, the most important textural property of yogurt. Confocal laser scanning microscopy revealed that the added ingredients played a major role in the formation of the gel network structure of the yogurt. Both Streptococcus thermophilus and Lactobacillus bulgaricus remained at acceptable levels > 8.28 Log CFU/g and > 5.79 Log CFU/g after 3 weeks at 4°C regardless of the added ingredients.

Technological potential of under-utilized starches from eight varieties of legumes grown in Cameroon

Starch samples from eight legumes cultivars instar of one variety of Vigna unguiculata L. (Cowpea), one variety of Vigna subterrenea V. (Bambara groundnut) and six varieties of Phaseolus vulgaris L. (Common bean), grown in Cameroon were isolated, and their physicochemical and pasting properties were evaluated. The objectives of the study were to investigate the starch properties and processing characteristics of different bean varieties, and to establish the basic foundation of improving the functionality of beans and their starch grown in the region. The result revealed significant differences amongst the properties of the starches. The swelling power of the legume starch isolates put them in the category of highly restricted-swelling starch. This characteristic is desirable for the manufacture of value-added products such as noodles and composite blends with cereals. The pasting properties were determined using a rapid visco analyzer, and various legumes bean starches exhibited different pasting profiles. The high breakdown viscosity (BV) was founded for Cowpea and Bambara groundnut and confirmed their low. ability to resist heat and shear stress when compared to Common bean varieties studies. The factors which influence the pasting characteristics resulting to decrease in peak viscosity (PV), trough viscosity (TV) and final viscosity (FV) of starch are attributed to the interaction of starch with the protein, fat, etc. which depended to their variety.

Use of starch-based fat replacers in foods as a strategy to reduce dietary intake of fat and risk of metabolic diseases

Cardiovascular disease (CVD) has emerged as one of the leading causes of death worldwide. Elevated blood cholesterol and low-density lipoprotein levels are crucial risk factors that contribute to the development of CVD and other metabolic diseases. Dietary fat is believed to be the key factor in modulating circulating cholesterol levels. Thus, reducing dietary intake of fat appears to be an effective strategy to reduce the risk of heart disease. Also, excessive intake of fat and high-calorie foods is also related to the development of obesity, which contributes to the development of CVD. Therefore, the consumption of low-fat low-calorie foods is part of a healthier dietary pattern. However, simply removing fat from foods may lead to compromised overall quality and reduced acceptance of the food products. Thus, fat replacers have emerged as ideal alternatives to dietary fat, which can not only reduce the overall fat and calorie content of the foods but also mimic the physiochemical properties of dietary fat. Starch-based fat replacers are one kind of fat mimetic that can be produced either chemically as modified starch or enzymatically as maltodextrins. Both modified starch and maltodextrins have been demonstrated to have a promising ability to improve the overall quality of reduced-fat foods. Modified starch granules act directly as fat globules in modulating the structure and sensory characteristics of the foods, whereas maltodextrins can form thermoreversible gels. Both modified starch granules and maltodextrins can create a fat-like mouthfeel and therefore are potential fat replacers. This review article aims to discuss the following topics: (a) the effect of carbohydrates and fat on human cardiovascular health and other disease risks, (b) the functionality of starch-based fat replacers in foods, (c) the applications of starch-based fat replacers in various foods, and (d) the current and future market value of starch-based fat replacers.

Influence of co-cultures ofStreptococcus thermophilus and probiotic lactobacilli on quality and antioxidant capacity parameters of lactose-free fermented dairy beverages containingSyzygium cumini(L.) Skeels pulp

This study investigated the influence of probiotic lactobacilli in co-culture with Streptococcus thermophilus on composition, physicochemical parameters, microbial viability, sensory acceptability, antioxidant capacity and protein profile of lactose-free fermented dairy beverages with added whey, β-galactosidase and jambolan (Syzygium cumini (L.) Skeels) pulp. Three beverages (T1, T2 and T3) were prepared with Streptococcus thermophilus TA-40 as starter culture. Lactobacillus rhamnosus LR32 and Lactobacillus casei BGP93 probiotic cultures were added into T2 and T3, respectively. The probiotic adjuvants slightly influenced the pH and titratable acidity of dairy beverages, with no influence on the proximate composition and on the sensory attributes. Samples presented fat and protein contents suitable to meet the requirements of “low-fat dairy beverages with non-dairy ingredients added” according to the Brazilian legislation, lactobacilli viability above 7 log CFU g⁻¹ for both probiotics and total phenolic content around 40 mg GAE 100 g⁻¹. Colour was the most evaluated sensory aspect (average scores close or higher than 8 in a scale from 0 to 10 for most of the sampling periods). The overall antioxidant capacity increased significantly following the addition of jambolan (p < 0.05), and significantly more during storage (p < 0.05), likely due to proteolysis verified in the electrophoresis gels, as a result of the metabolism of the lactic cultures. The dairy beverages studied are good options for functional foods due to their nutritional value, viability of probiotic lactobacilli, phenolic content, and antioxidant capacity, also serving lactose-intolerant people.

Probiotic dairy beverages for lactose intolerants had lactobacilli viability above 7 log CFU for 21 days. The co-cultures studied showed proteolytic activity and reinforced the effect of the jambolan pulp on the antioxidant capacity of the products.

Effect of modified tapioca starch on the physicochemical and sensory properties of liquid kashk

Three forms of modified tapioca starch, i.e. phosphorylated cross-linked tapioca starch (CLTS), octenyl succinic anhydride substituted tapioca starch (OSTS) and hydroxypropylated tapioca starch (HPTS) were studied and used as stabilizers (0.5, 1 and 1.5%) in industrial liquid kashk, and their effects on the physicochemical and sensory properties of products were examined during 60 days of refrigerated storage. When combined with the highest concentration of each stabilizer, the kashk reached its highest acidity, hardness, adhesiveness, viscosity and overall acceptability, while the lowest value of syneresis was obtained. Moreover, the highest values of viscosity was observed after incorporating CLTS into the samples, and other samples with HPTS showed the highest syneresis, hardness, adhesiveness and overall acceptability. During storage, there were significant trends of increase in the values of acidity, syneresis and hardness, whereas the viscosity, pH and adhesiveness decreased significantly. Several sensory attributes such as texture, odour value and overall acceptability were influenced by the type of stabilizer. In general, among the three kinds of modified tapioca starch, the HPTS was the most suitable form at the concentration of 1.5%, and this was most appropriate for the production of industrial liquid kashk with respect to high-quality physicochemical and sensory properties.

Jujube mucilage as a potential stabilizer in stirred yogurt: Improvements in the physiochemical, rheological, and sensorial properties

Here, the mucilage of jujube was extracted and used as a natural stabilizer in the production of stirred yogurt. Yogurts were enriched with different concentrations of jujube mucilage (i.e., 0, 0.1, 0.15, and 0.2%), and their physical, chemical and sensory attributes were analyzed during 21 days of storage at 4°C. The results showed that the protein and fat contents of the yogurts were not significantly different compared with each other, while higher ash contents were obtained in yogurts which contained higher concentrations of the mucilage. The acidity and proteolysis of the stirred yogurts were enhanced in the presence of mucilage, and they exhibited lower concentrations of diacetyl and acetaldehyde, although the differences were not significant among the samples of different treatments. The storage time had adverse and direct effects on the amounts of acetaldehyde and diacetyl, respectively. The effects of storage time and the presence of jujube mucilage in yogurts caused a significant decrease in the percentage of syneresis, while their viscosity and WHC values increased. The magnitudes of dynamic moduli (G, G''), complex viscosity (η*), and loss tangent (tan δ) of stirred yogurts increased by increasing the concentration of jujube mucilage. The yogurts which had been enriched with mucilage were preferred slightly less by tasters during the storage period, but these differences did not amount to a statistical significance. Generally, the results of the present study showed that the jujube mucilage can be potentially used as a natural stabilizer in stirred yogurt.

Syneresis investigations of lacto-fermented sodium caseinate in a mixed model system

BACKGROUND

The textural characteristics of fermented dairy products are important quality parameters that play a major role in their stability and consumer's acceptance. The aim of this study was to investigate the influence of sodium caseinate, starch, lactose and lactic acid bacteria as ferment on the syneresis in a mixed model system, and to evaluate their impact on the acid gel formation throughout pH and zeta potential monitoring. Accordingly, a protocol was designed to perform an experimental design by using a mixture of the selected factors.

RESULTS

A significant decrease of syneresis was detected in all mixtures at 8% of sodium caseinate, ranging between a minimum of 1.8% and a maximum of 20.6% compared to the mixtures at 3% of sodium caseinate in which the syneresis decrease had ranged between a minimum of 22.2% and a maximum of 47.8%. The addition of starch had a significant impact on the acidification profile and on the syneresis of the fermented mixed model. Moreover, the monitoring of pH and zeta potential during the lacto-fermentation process has also led to a better understanding of the acid gelation and the syneresis variations.

CONCLUSION

Syneresis varies very closely with sodium caseinate concentration, starch concentration and also with their association, regardless of the concentrations of lactose and ferment. In fact syneresis could be reduced to an optimum level if a sodium caseinate-starch mixed system is employed: Less syneresis gels could be obtained at a sodium caseinate concentration above 5% if starch is used above 1%.

Carbohydrates as Fat Replacers

The overconsumption of dietary fat contributes to various chronic diseases, which encourages attempts to develop and consume low-fat foods. Simple fat reduction causes quality losses that impede the acceptance of foods. Fat replacers are utilized to minimize the quality deterioration after fat reduction or removal to achieve low-calorie, low-fat claims. In this review, the forms of fats and their functions in contributing to food textural and sensory qualities are discussed in various food systems. The connections between fat reduction and quality loss are described in order to clarify the rationales of fat replacement. Carbohydrate fat replacers usually have low calorie density and provide gelling, thickening, stabilizing, and other texture-modifying properties. In this review, carbohydrates, including starches, maltodextrins, polydextrose, gums, and fibers, are discussed with regard to their interactions with other components in foods as well as their performances as fat replacers in various systems.

Effect of 2 types of resistant starches on the quality of yogurt

This study investigated the effects of resistant starch (RS) 2 (a high-amylose corn starch) and RS3 (physically modified corn starch) on yogurt quality. Yogurt containing Bifidobacterium BB-12 was treated with RS2 or RS3 to a final concentration of 1.5%, with the control group receiving 1.5% (wt/wt) of sucrose. Multispeckle diffusing wave spectroscopy and scanning electron microscopy were used to investigate the effect of the resistant starches on the gelation process and microstructure of yogurt. The quality of the yogurt treatments was evaluated using viable counts of Bifidobacterium BB-12 and all viable cells, titratable acidity, amount of whey separation, and viscosity during storage. The resistant starches affected the progress of gelation and microstructure and decreased the decline of viable counts of Lactobacillus. Notably, RS3 effectively protected the Bifidobacterium BB-12, increased the viscosity, and decreased titratable acidity. Our results suggested that RS could improve the quality of yogurt and have a more probiotic effect. Further studies could lead to optimization in yogurt processing by mixing these 2 types of RS to determine their best usage and explore their interactions with proteins.

Effect of poly-γ-glutamic acid on the stability of set yoghurts

The effects of poly-γ-glutamic acid (γ-PGA) on the stability of yogurt were studied in terms of texture, rheology, particle size, and microstructure. The effects of γ-PGA on the pH and water holding capacity (WHC) of yogurt during refrigeration were also studied. The tan δ value of the yogurt with 0.04% (w/w) γ-PGA was significantly lower than that of control. The addition of γ-PGA decreased the particle size. The yogurt with 0.02% (w/w) γ-PGA had denser network structure with less porosity, and cross-linking between complexes occurred with greater frequency. The pH of the yogurt supplemented with 0.02% and 0.04% γ-PGA was significantly higher. WHC increased with the amount of γ-PGA. The addition of γ-PGA to yogurt strengthened the antishear ability, inhibited the postacidification phenomenon, and improved stability during refrigeration.

Application of new insoluble dietary fibres from triticale as supplement in yoghurt - effects on physico-chemical, rheological and quality properties

BACKGROUND

The need to increase the daily intake of dietary fibres opens a new chapter in the research of functional foods enriched with fibres. The potential application of an innovative product - insoluble dietary fibres from triticale in yoghurts - was deployed by characterising their food application and evaluating physico-chemical, rheological and sensory properties and was the aim of this research.

RESULTS

Detailed characterisations of these fibres are presented for the first time and showed very good hydration properties, optimal pH (slightly acidic), optimal chemical composition, high antioxidant capacity which was proven by phenolics contents. Besides, these fibres showed negligible calorific value, with no phytates and high antioxidant capacity, mainly from ferulic acid. Therefore they could be successfully added to yoghurt. Enrichment of yoghurt having different milk fat content (1.5 and 2.8% w/w) with triticale insoluble fibre (1.5% and 3.0% w/w) significantly influenced the syneresis level, its apparent viscosity, yield stress and thixotropic behaviour. The overall sensory quality scores indicated that yoghurt enriched with 1.5% triticale insoluble fibres was recognised as 'excellent' and had enhanced antioxidant activity.

CONCLUSIONS

Insoluble triticale fibre could therefore be used as a supplement to produce functional yoghurt. © 2017 Society of Chemical Industry.