Plant and Dairy-Based Yogurts: A Comparison of Consumer Sensory Acceptability Linked to Textural Analysis

Transethosomal gel for enhancing transdermal delivery of natural therapeutics

Transethosomes, a fusion of transferosomes and ethosomes, combine the advantageous attributes of both vesicular systems to enhance deformability and skin permeation. While skin delivery is effective for drug transport, overcoming the skin barrier remains a significant challenge, particularly for plant-based products with poor permeability. Transethosomes offer a promising solution, but their low viscosity and retention on skin surfaces led to the development of transethosomal gels. These gels can entrap unstable and high molecular weight herbal extracts, fractions and bioactive compounds, facilitating enhanced drug delivery to the inner layers of the skin. This review focuses on the superior performance of transethosomes compared with conventional lipid-based nanovesicular systems, offering an advanced approach for transdermal delivery of plant-based drugs with improved permeability and stability.

A novel approach has been developed to produce pure plant-based gel soy yogurt by combining soy proteins (7S/11S), high pressure homogenization, and glycation reaction

This research sought to examine how the physicochemical characteristics of soy globulins and different processing techniques influence the gel properties of soy yogurt. The goal was to improve these gel properties and rectify any texture issues in soy yogurt, ultimately aiming to produce premium-quality plant-based soy yogurt. In this research study, the investigation focused on examining the impact of 7S/11S, homogenization pressure, and glycation modified with glucose on the gel properties of soy yogurt. A plant-based soy yogurt with superior gel and texture properties was successfully developed using a 7S/11S globulin-glucose conjugate at a 1:3 ratio and a homogenization pressure of 110 MPa. Compared to soy yogurt supplemented with pectin or gelatin, this yogurt demonstrated enhanced characteristics. These findings provide valuable insights into advancing plant protein gels and serve as a reference for cultivating new soybean varieties by soybean breeding experts.

Effect of Blueberry Pomace Addition on Quality Attributes of Buttermilk-Based Fermented Drinks during Cold Storage

The fruit and beverage industry faces challenges related to waste management and environmental pollution due to rapid industrial expansion. Fruit industry waste, such as blueberry pomace, holds the promise of enhancing gut health and providing valuable antioxidants. Concurrently, buttermilk, a prominent dairy product, offers nutritional and technological benefits but remains underutilized. This study aimed to evaluate the incorporation of blueberry pomace (0%, 2%, 4%, 6%, 8%, and 10%) into buttermilk at varying levels and assess its impact on the physicochemical, antioxidant, microbiological, and sensory characteristics of the buttermilk. Buttermilk samples were supplemented with different concentrations of blueberry pomace and subjected to analysis over a two-week storage period (4 ± 1 °C). The addition of blueberry pomace led to alterations in the pH, dry matter, water holding capacity, color parameters, total phenolic content, and antioxidant activity. Microbiological analysis revealed the absence of Enterobacteriaceae, yeast, or molds. Sensory evaluation indicated significant differences among samples, with the highest scores observed for the buttermilk supplemented with 2% and 4% blueberry pomace. Incorporating blueberry pomace improved the overall acceptability and sensory properties. This research highlights the potential of fruit industry by-products to enhance the functionality and health benefits of dairy products, which is a promising way to effectively utilize waste.

Investigation into the Sensory Properties of Plant-Based Eggs, as Well as Acceptance, Emotional Response, and Use

Consumers have become interested in plant-based alternatives to animal-based products. One of the under-studied alternatives is plant-based eggs (PBEs). This research investigated PBEs relative to conventional eggs and tofu scramble-another plant-based alternative. Firstly, participants (n = 93) completed a word association task asking them about PBEs. Participants then evaluated the different food samples using hedonic scales, check-all-that-apply (CATA), and temporal check-all-that-apply (TCATA), as well as identified their emotional response and proposed use for PBEs. Participants were interested in plant-based alternatives, including PBEs, but they were concerned about the sensory properties. When they evaluated the different samples, the flavour and texture of the PBEs were disliked in comparison to the eggs. This result may be due to the beany, bitterness, and off-flavour attributes associated with the PBEs. Participants also associated the PBEs with negative emotions. The liking of tofu scramble was not significantly different from the eggs, and the eggs and tofu scramble were mainly associated with positive emotions. During the TCATA evaluation, the participants focused on the flavour attributes of PBEs, while their evaluation of the eggs was dominated by the textural attributes. Whether following a plant-based diet or not, consumers are interested in PBEs, but the sensory properties of PBEs need to be improved before they are willing to adopt them into their diet. This study is one of the first to evaluate the sensory properties of PBEs, as well as consumers' emotional response to them and their attitudes about PBEs.

Legume milk-based yogurt mimetics structured using glucono-δ-lactone

The potential to produce protein-structured vegan yogurts with legumes was explored to offer an alternative to conventional polysaccharide-based varieties. Glucono-δ-lactone (GDL) was employed as a slow acidifying agent and was investigated for its ability to generate cold-set, yogurt-like gels using soy and lentil milks made using minimal processing steps. Soy (5.3 % protein) and lentil (6.1 % protein) milks were successfully gelled by GDL at concentrations of 0.5 % and 1 % w/w. Soy and lentil milks experienced similar acidification profiles and demonstrated good fits with double-exponential decay models. The physical properties of these legume gels were evaluated and compared to a commercial stirred dairy yogurt. Penetration tests were carried out on intact gels, then repeated after stirring. All intact soy samples demonstrated significantly stronger gel structures compared to the commercial yogurt, and most experienced greater amounts of brittleness. Results showed that the stirring of gels caused a notable decrease in firmness and brittleness in the soy gels, making them more similar to the control. Power-law modelling of viscosity curves demonstrated that all samples experienced non-Newtonian flow behavior (n < 0.29). Susceptibility to syneresis was measured by the degree of liquid loss following centrifugation. The optimization of protein type and GDL concentration to replicate the physical properties of dairy-based yogurts can enhance their consumer acceptance and provide a more customizable and controlled approach alternative to traditional fermentation methods.

Plant-Based Emulsions as Dairy Cream Alternatives: Comparison of Viscoelastic Properties and Colloidal Stability of Various Model Products

In the context of growing interest in plant-based food products for their potential health benefits and sustainability, this study investigates the effect of mono- and diglycerides of fatty acids application on physico-chemical properties of various plant-based cream products, compared to lecithin application in rice cream. Rheological and textural parameters, colour profile, and colloidal stability were analysed. The application of mono- and diglycerides modified the creams' viscoelastic behaviour, showing a decrease in viscoelasticity across the samples; although in oat-coconut cream resulted in a higher viscoelasticity, indicating the formation of a gel-like structure. Rice cream with lecithin emulsifier showed lower viscoelastic properties characterised by higher phase angle (tan δ). All samples behaved as pseudoplastic materials (with a flow behaviour index n < 1). For coconut and almond creams, the consistency coefficient increased and flow behaviour index decreased after emulsifier application. Interestingly, the emulsifier addition did not significantly affect the cream's colour profile, characterised by yellow hue angle (h*) as a dominant spectral component. The colloidal stability, indicated by a stability index (SI), was determined as well.

Comparison of Physical and Compositional Attributes between Commercial Plant-Based and Dairy Yogurts

A primary strategy led by the food industry to improve the sustainability of the agricultural food supply is the development of modern plant-based alternatives. The information provided via marketing and product packaging provides consumers with the expectation that these products provide a similar product experience to conventional products, yet it is not well understood whether these commercial alternative products are comparable to traditional animal-based products. To aid in developing improved plant-based products, this study aimed to compare the quality and physical attributes of commercially available plant-based and dairy yogurts. Using instrumental methods, commercially available yogurt products were analyzed for their pH, titratable acidity, color, water activity, moisture content, and rheology, which included 13 plant-based (almond, cashew, coconut, oat, soy) and 8 whole-milk dairy yogurts. The present study reveals that the plant-based and dairy yogurts had no significant differences in pH, lactic acid, water activity, or moisture content. However, there were significant differences in the color and texture properties between the plant-based and dairy yogurts. Additionally, significant differences were observed across the plant-based yogurt products in terms of their color and texture properties. This highlights the need for additional studies to determine how individual ingredients influence the physical characteristics and textural properties to direct the development of plant-based yogurts. Improving upon the physicochemical properties of plant-based yogurt may encourage more consumers to adopt a more sustainable diet.

Exploring the Role of Lactic Acid Bacteria Blends in Shaping the Volatile Composition of Fermented Dairy and Rice-Based Beverages: A Step towards Innovative Plant-Based Alternatives

Plant-based products are currently gaining consumers' attention due mainly to the interest in reducing the consumption of foods of animal origin. A comparison of two fermentative processes utilizing dairy milk and a rice beverage was conducted in the present study, using a commercial lactic acid bacteria strain combination (CH) and a selected mixture of lactic acid bacteria from yogurt (LLV). Cell viability and physicochemical characteristics (total soluble solids, pH, total acidity) were determined to describe the samples before and after fermentation, as well as the volatile composition (gas chromatography-mass spectrometry) and the sensory profile (Rate-All-That-Apply test). Results of the analyses showed significant differences among samples, with a clear effect of the raw material on the volatile profile and the sensory characterization, as well as a significant effect of the microbial combination used to ferment the matrices. In general, the selected LLV strains showed a greater effect on both matrices than the commercial combination. Dairy samples were characterized by a volatile profile represented by different chemical families (ketones, lactones, acids, etc.), which contributed to the common descriptive attributes of milk and yogurt (e.g., dairy, cheese). In contrast, rice beverages were mainly characterized by the presence of aldehydes and alcohols (cereal, legume, nutty).

Formulations and assessments of structure, physical properties, and sensory attributes of soy yogurts: Effect of carboxymethyl cellulose content and degree of substitution

Soy yogurts present challenges, including absence of tender and slipperiness mouthfeel, and poor stability. This study aimed to investigate the impacts of carboxymethyl cellulose (CMC) with degrees of substitution of 0.7 (CMC0.7) and 1.2 (CMC1.2) at concentrations ranging from 0 % to 1.1 % on the stability, microstructure, rheology, tribology, and mouthfeel of soy yogurts. As the CMC concentration increased from 0 % to 0.3 %, soy yogurts displayed a coarser microstructure, decreased stability, and increased gel strength. As the concentration of CMC further increased from 0.5 % to 1.1 %, soy yogurts exhibited trends of a smoother microstructure, increased stability, and softer gel strength. Notably, soy yogurts with CMC0.7 demonstrated a superior water holding capacity (WHC) than soy yogurts with CMC1.2. Tribological measurements indicated that soy yogurts with CMC0.7 at a 0.7 % concentration had the lowest coefficient of friction (COF) value among most sliding speeds, showing a 23 % reduction compared to soy yogurts without CMC at a sliding speed of 10 mm/s. Moreover, sensory evaluation showed that soy yogurts with CMC0.7 at a 0.7 % concentration had the highest total score in mouthfeel evaluation. Therefore, the addition of CMC0.7 within the concentration range of 0.5 % to 1.1 % may produce stable and delicate yogurts.

Physical and Chemical Properties, Flavor and Organoleptic Characteristics of a Walnut and Purple Rice Fermented Plant Drink

In recent years, green and healthy foods have attracted much attention. Plant-based foods have become an alternative to animal-derived foods. In this study, we used walnut and purple rice as the primary raw materials to produce a fermented plant drink. The process included boiling, mixing, grinding, inoculation, fermentation, and sterilization. We then analyzed the similarities and differences between the resulting walnut and purple rice fermented plant drink and an unfermented walnut and purple rice plant drink, as well as dairy-based yoghurt, in terms of physical chemistry, flavor, and sensory characteristics. We also examined the similarities and differences between the walnut and purple rice fermented plant drink and room-temperature yoghurt. The study results revealed that the walnut and purple rice fermented plant drink exhibited greater viscosity than the walnut and purple rice unfermented plant drink and room-temperature yoghurt. Additionally, the former displayed enhanced stability and recovery ability. Notably, distinguishable differences were observed between the three samples in terms of the presence of unknown volatiles and the umami signal, as indicated by electronic nose/tongue and GC-IMS analyses. The umami flavor of the walnut and purple rice fermented plant drink surpasses that of room-temperature yoghurt, while its taste is less salty than that of the walnut and purple rice plant drink. Despite possessing a weaker aroma than dairy-based yogurt, it is more potent than the walnut and purple rice plant drink. Additionally, its relative abundance of olefins, ketones, and alcohols enhances its unique flavor profile, surpassing both other options. Based on sensory analysis, it can be deduced that walnut and purple rice fermented plant drink has the highest overall acceptance rate.

Exploring the textural dynamics of dairy and plant-based yoghurts: A comprehensive study

The mouthfeel and texture of dairy and non-dairy yoghurts play a critical role in food acceptance and liking. The present study aimed to understand the oral perception of commercially available dairy and non-dairy yoghurts. Four dairy and four non-dairy yoghurts with different levels of protein and fat were analyzed to understand the impact of particle size, textural properties and frictional coefficient on the dynamic sensory mouthfeel characteristics measured by the temporal dominance of sensations (TDS) method. Differences in friction coefficients of dairy and non-dairy yoghurts were observed. The friction factor was lower for high-fat dairy yoghurts than for non-dairy yoghurts. The particle size d₉₀ in yoghurts was positively related to graininess perception (r=0.81) and negatively associated with mouthfeel liking (r=-0.87) and overall liking (r=-0.80). For the TDS results, "creaminess" and "thickness" were significantly dominant for dairy yoghurts, while "melty" and "easy to dissolve" were dominant attributes for non-dairy yoghurts. Creaminess perception improves the mouthfeel liking (r=0.72) and overall liking (r=0.59) of yoghurts and is the driver of liking. The findings of this study help understand the intrinsic mouthfeel properties of commercial dairy and non-dairy yoghurts, which will provide valuable insight to product developers during the new product formulation.

A comparison of the nutritional profile and nutrient density of commercially available plant-based and dairy yogurts in the United States

Introduction

Plant-based yogurts are sustainable alternatives to dairy yogurts, but a nutritional comparison of plant-based yogurts within the context of dairy yogurts has not yet been applied to commercially available products in the United States. Dairy yogurts provide significant dietary nutrients, and substituting plant-based yogurts may have unintended nutritional consequences. The objective of this study was to compare the macronutrient and micronutrient values of commercially available plant-based and dairy yogurts launched between 2016 and 2021.

Methods

Nutritional information for yogurts were collected through Mintel Global New Products Database, and products were categorized according to their primary ingredient. Regular-style yogurts (n = 612) were included in this study: full-fat dairy (n = 159), low and nonfat dairy (n = 303), coconut (n = 61), almond (n = 44), cashew (n = 30), and oat (n = 15). We utilized the Nutrient Rich Foods (NRF) Index, a comprehensive food guidance system that assigns a score based on the nutrient density of individual foods. This allowed us to compare the nutritional density of the yogurts based on nutrients to encourage (protein, fiber, calcium, iron, potassium, vitamin D) and nutrients to limit (saturated fat, total sugar, sodium).

Results

Compared to dairy yogurts, plant-based yogurts contained significantly less total sugar, less sodium, and more fiber. However, plant-based yogurts contained significantly less protein, calcium, and potassium than dairy yogurts. The yogurts were ranked from the highest to lowest nutrient density based on the NRF Index as follows: almond, oat, low and nonfat dairy, full-fat dairy, cashew, and coconut. Almond yogurts scored significantly higher than all other yogurts, indicating the highest nutrient density.

Discussion

The highest NRF scores were awarded to almond and oat yogurts, likely a result of their low levels of total sugar, sodium, and saturated fat. By applying the NRF model to plant-based and dairy yogurts, we have identified opportunities for the food industry to improve the formulation and nutritional composition of plant-based yogurts. In particular, fortification is an opportunity to improve plant-based yogurt nutritional properties.

Consumer perception of plant-based yoghurt: Sensory drivers of liking and emotional, holistic and conceptual associations

Plant-based (PB) yoghurts is a rapidly expanding food category with the potential to reduce many of the negative environmental impacts associated with the farming of dairy cattle and related greenhouse gas emissions. Within the context of growing consumer demand for PB products, this research aimed to identify the main drivers of consumer acceptance of PB yoghurts through data drawn from a consumer study of 113 adult New Zealand participants who tasted a representative range of commercially available vanilla-flavoured PB yoghurts, and provided sample evaluations using a multi-variable measurement approach comprised of liking ratings, emotional responses, sensory characterisations, and holistic / conceptual perceptions. The primary finding of this study was that the overall acceptability of currently available PB yoghurts is low, leading to poor attitudes and low willingness to consume PB yoghurts. The examined products were characterised by the presence of several sensory attributes that negatively impacted consumer liking, either because they were unexpected or because their intensity level was too high. Among the main sensory issues identified were perceived sourness (acidity), lumpy appearance and non-white colour. In contrast, vanilla flavour and a creamy/smooth texture were identified as the main drivers of liking. The multi-response approach used in this study enabled a comprehensive characterisation of the products. One of the key insights gained was that negative emotional activation, caused by the presence of unexpected sensory attributes in the samples, was the main driver of product rejection. This was likely due to the disparity between consumers' sensory expectations, formed primarily based on their experience with dairy yoghurts, and the actual experience upon tasting the PB yoghurts. Overall, the findings indicate that the sensory properties of currently available PB yoghurts are a significant barrier to their adoption by most consumers and that addressing these sensory deficiencies is essential to achieving mainstream market acceptance of these products.

The influence of the texture and color of goat’s salad cheese on the emotional reactions of consumers compared to cow’s milk cheese and Feta cheese

In this study, the sensory and mechanical aspects of the texture of goat’s milk salad cheese were correlated with the emotional profiles of consumers. Using descriptive sensory analysis and instrumental assessment, the texture profile of goat’s milk salad cheese was compared to cow’s milk salad cheese and Feta cheese. Texture measurements confirmed that goat’s cheese compared to cow’s cheese had more softness and less hardness, and Feta cheese had the highest whiteness index compared to the other cheeses. Goat’s milk salad cheese was much less acceptable to consumers compared to cow’s milk cheese and Feta cheese. Consumers also indicated that the hardness of goat’s cheese was lower than that of cow’s cheese and Feta cheese. A reduction in “stickiness” in comparison with cow’s cheese was also reported; however, it was much higher than that for Feta cheese. The “fracturability” and “graininess” of goat’s cheese was similar to cow’s cheese. Emotional profile analysis showed that goat’s cheese evokes mainly negative emotions. Consumers indicated only one positive emotion in the case of this cheese, which was “healthy”. The most frequently mentioned emotions after the consumption of goat’s cheese were “upset”, “disgusted” and “worried”. Many consumers also indicated “disappointed” and “angry”, which did not occur after the consumption of cow’s cheese. This research shows how important it is to combine several analyses and techniques when evaluating dairy products, including salad cheeses. It is also important that consumer research is enriched by emotional profiling.

Graphical abstract

Digital technologies to assess yoghurt quality traits and consumers acceptability

BACKGROUND

Sensory biometrics provide advantages for consumer tasting by quantifying physiological changes and the emotional response from participants, removing variability associated with self-reported responses. The present study aimed to measure consumers' emotional and physiological responses towards different commercial yoghurts, including dairy and plant-based yoghurts. The physiochemical properties of these products were also measured and linked with consumer responses.

RESULTS

Six samples (Control, Coconut, Soy, Berry, Cookies and Drinkable) were evaluated for overall liking by n = 62 consumers using a nine-point hedonic scale. Videos from participants were recorded using the Bio-Sensory application during tasting to assess emotions and heart rate. Physicochemical parameters Brix, pH, density, color (L, a and b), firmness and near-infrared (NIR) spectroscopy were also measured. Principal component analysis and a correlation matrix were used to assess relationships between the measured parameters. Heart rate was positively related to firmness, yaw head movement and overall liking, which were further associated with the Cookies sample. Two machine learning regression models were developed using (i) NIR absorbance values as inputs to predict the physicochemical parameters (Model 1) and (ii) the outputs from Model 1 as inputs to predict consumers overall liking (Model 2). Both models presented very high accuracy (Model 1: R = 0.98; Model 2: R = 0.99).

CONCLUSION

The presented methods were shown to be highly accurate and reliable with respect to their potential use by the industry to assess yoghurt quality traits and acceptability. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Heterofermentative lactic acid bacteria such as Limosilactobacillus as a strong inhibitor of aldehyde compounds in plant-based milk alternatives

Reduction of greenhouse gas emissions is important to limit climate change. Because ruminant animals emit greenhouse gases, the worldwide plant-based alternative market is an emerging trend for eating less meat and dairy products. To produce plant-based dairy products such as yogurt alternatives, certain lactic acid bacterial species, which are used for cow's milk fermentation, are often used. Substrate changes from cow's milk to plant-based milk caused nutritional changes, and unsaturated fatty acids are more enriched in plant-based milk alternatives than in cow's milk. Unsaturated fatty acids can lead to the formation of aldehydes, some of which are off-flavors; therefore, substrate changes have the potential to alter the suitable lactic acid bacterial species used for fermentation to control flavor formation, such as aldehyde compounds. However, differences in the effect of the fermentation processes on aldehyde compounds have not been evaluated among lactic acid bacterial species. In this study, we comprehensively evaluated the effect of lactic acid bacterial fermentation on aldehyde compounds in synthetic medium and plant-based milk alternatives using 20 species of lactic acid bacteria. Heterofermentative lactic acid bacteria such as strains belonging to Limosilactobacillus had a strong aldehyde-reducing ability, likely from differences in alcohol dehydrogenase function. Because the odor detection threshold of ethanol compounds was lower than that of their equivalent aldehyde compounds, our findings are valuable for the fermentation of plant-based milk alternatives with lactic acid bacteria with the goal of decreasing off-flavors derived from aldehyde compounds.

The Impact of Vanilla and Lemon Aromas on Sensory Perception in Plant-Based Yogurts Measured with Static and Dynamic Methods

The application of cross-modal interaction is a potential strategy to tackle the challenges related to poor sensory properties, such as thin mouthfeel, in plant-based yogurts. Thus, we aim to study the influence of aroma compounds possibly congruent with sweetness on the perceived sensory profile. Descriptive analysis and temporal dominance of sensations (n = 10 × 4) with a trained panel were conducted with and without a nose clip. One unflavored sample and samples flavored with either lemon or vanilla aromas were included (vanilla; 0.05%; 0.1%; lemon: 0.025%; 0.05%). Odor intensity, thick, sticky, and melting sensation, sweetness, and grain-like flavor were evaluated on an unstructured 10-cm line scale with anchors and reference samples. The results demonstrate how vanilla and lemon aromas suppressed grain-like flavor and enhanced odor intensity and sweetness. The following order was detected among samples in perceived sweetness intensity: unflavored < lemon < vanilla. The two sessions with and without nose clip differed statistically in sweetness, highlighting that the aromas impacted the perceived sweetness but not the mouthfeel in vanilla samples. The study suggests that congruent aromas could modify the perceived sweetness in plant-based yogurts; however, aroma or perceived sweetness does not impact the mouthfeel in plant-based yogurts. While the odor−taste interaction in such products is evident, the study highlights that aroma compounds alone do not modify mouthfeel.

Physicochemical Properties and Mouthfeel in Commercial Plant-Based Yogurts

There is a growing need for plant-based yogurts that meet consumer demands in terms of texture. However, more research is required to understand the relationship between physicochemical and mouthfeel properties in plant-based yogurts. The purpose of this study was to determine the physicochemical properties of five commercial plant-based yogurt alternatives with different chemical compositions, making comparisons to dairy yogurts and thick, creamy, thin, and watery mouthfeel sensations. The physicochemical parameters studied included large and small deformation rheology, particle size, soluble solids, acidity, and chemical composition. Significant differences in flow behavior and small deformation rheology were found between dairy- and plant-based yogurts. Among plant-based yogurts thick, creamy, thin, and watery mouthfeel sensations were strongly associated with steady shear rates and apparent viscosity. The results highlight the importance of large deformation rheology to advance the use of plant-based ingredients in the development of yogurt alternatives. Furthermore, this study demonstrates that dairy- and plant-based yogurts with a similar mouthfeel profiles may have different viscoelastic properties, which indicates that instrumental and sensory methods should not be considered substitutive but complementary methods when developing plant-based yogurts in a cost-effective and timely manner.