Enhancing expected food intake behaviour,hedonics and sensory characteristics of oil-in-water emulsion systems through microstructural properties,oil droplet size and flavour

Food reformulation, either to reduce nutrient content or to enhance satiety, can negatively impact upon sensory characteristics and hedonic appeal, whilst altering satiety expectations. Within numerous food systems, perception of certain sensory attributes, known as satiety-relevant sensory cues, have been shown to play a role in food intake behaviour. Emulsions are a common food structure; their very nature encourages reformulation through structural design approaches. Manipulation of emulsion design has been shown to change perceptions of certain sensory attributes and hedonic appeal, but the role of emulsions in food intake behaviour is less clear. With previous research yet to identify emulsion designs which promote attributes that act as satiety-relevant sensory cues within emulsion based foods, this paper investigates the effect of oil droplet size (d_4,3: 0.2–50 μm) and flavour type (Vanilla, Cream and No flavour) on sensory perception, hedonics and expected food intake behaviour. By identifying these attributes, this approach will allow the use of emulsion design approaches to promote the sensory characteristics that act as satiety-relevant sensory cues and/or are related to hedonic appeal. Male participants (n = 24) assessed the emulsions. Oil droplet size resulted in significant differences (P < 0.05) in ratings of Vanilla and Cream flavour intensity, Thickness, Smoothness, Creamy Mouthfeel, Creaminess, Liking, Expected Filling and Expected Hunger in 1 h’s time. Flavour type resulted in significant differences (P < 0.05) in ratings of Vanilla and Cream flavour intensity, Sweetness and Liking. The most substantial finding was that by decreasing oil droplet size, Creaminess perception significantly increased. This significantly increases hedonic appeal, in addition to increasing ratings of Expected Filling and decreased Expected Hunger in 1 h’s time, independently of energy content. If this finding is related to actual eating behaviour, a key target attribute will have been identified which can be manipulated through an emulsions droplet size, allowing the design of hedonically appropriate satiating foods.     

A low-calorie beverage supplemented with low-viscosity pectin reduces energy intake at a subsequent meal

The addition of fiber to foods and beverages has been linked with greater satiety and reduced energy intakes at the next meal. However, measures of satiety can be influenced by the time interval between beverage consumption and the next meal. The objective of this study was to determine how the time interval between consumption and a subsequent test meal impacts the satiating power of a low-calorie beverage supplemented with low-viscosity pectin fiber. Forty-two participants (20 men, 22 women) each participated in 4 study sessions. Study preloads were 2 low-calorie beverages (355 mL, 8 kcal) containing either 0 g fiber (no fiber) or 8 g low-viscosity fiber (added fiber). These preloads were consumed either 90 min before lunch or 15 min before lunch. Every 15 min, participants rated hunger, desire to eat, fullness, and thirst using 100-mm visual analogue scales. A test lunch was served and plate waste was measured. Beverages with added fiber reduced energy intakes at lunch relative to those without fiber. A short delay (15 min) between beverage consumption and a subsequent meal was associated with higher satiety ratings and reduced energy intakes, regardless of fiber content. The addition of low-viscosity pectin to low-calorie beverages reduced energy intakes at the next meal, presenting a possible tool for intake regulation. A short time interval between consumption of a low-calorie beverage and a meal also increased satiety and decreased food intake, reflecting the short-lived effect of volume.     

Comparison of partial and global projective mapping with consumers: A case study with satiating cheese pies

In the present work the performance of global projective mapping and partial projective mapping based on texture and flavor for sensory characterization of a novel food category (satiating food product) was compared. Eight different fresh-cheese pie formulations were designed to obtain different sensory (principally texture) characteristics which could affect expected satiating perception. Three groups of consumers evaluated the samples using one of the following methodologies: global projective mapping (G-PM) (n = 47), partial projective mapping based on flavor (F-PM) (n = 53), and partial projective mapping based on texture (T-PM) (n = 61). In addition, the expected satiating capacity of each cheese pie sample was scored on a nine-point scale. Results showed that the vocabulary used by consumers for describing the sensory characteristics of samples did not largely differ between global and partial projective mapping tasks. However, T-PM and F-PM tasks provided more detailed information than G-PM in each specific modality. Results suggested that when consumers performed the global projective mapping task they mainly took into account flavor characteristics for evaluating global similarities and differences among samples. In addition, hedonic attributes were more frequently mentioned in G-PM. Fresh cheese, sugar, corn starch and egg were the basic ingredients that conferred the fresh-cheese pies their typical, characteristic flavor and texture. The addition of whey or soy proteins, wheat bran or glucomannan increased expected satiating capacity which could be related to changes in texture (harder, more compact) leading to longer orosensory exposure. The addition of glucomannan caused the largest changes in the sensory characteristics of the cheese pies which in turn would be related to a decrease in perceived flavor intensity. Studying the interplay between formulations, sensory characteristics, expected satiating capacity and consumer liking could largely contribute to the development of this novel food category.     

The effect of viscosity and volume on pleasantness and satiating power of rice milk

The present study examined the influence of two viscosity levels (62.3 and 3.2 mPa s relative) either matched for taste or non-adjusted, and two volumes (500 and 250 ml) in a rice milk beverage on satiety and pleasantness. The separate viscosity treatments were isocaloric. Seventy-one participants consumed one of the samples in a fasted state between the hours of 8:30–9:30 a.m. Participants rated thirst and hunger prior to consumption, and then thirst, hunger, overall pleasantness, pleasantness of taste, and pleasantness of viscosity immediately post-consumption. The time to consumption of lunch was measured using food diaries. This procedure was repeated for five consecutive days. Significantly greater reductions of hunger, and longer times to lunch were observed with the 500 ml treatments, but not with the thickened treatments. Results indicate that the volume of a rice milk beverage consumed in place of a breakfast has more satiating effect than the viscosity. Moreover, a change in overall pleasantness ratings, and pleasantness of taste ratings over time was found, demonstrating the importance of repeat testing for hedonic ratings of novel foods.     

What is satiating? Consumer perceptions of satiating foods and expected satiety of protein-based meals

Designing food items with high satiating capacity is an area of increasing interest. It would be desirable for consumers to be able to make informed choices about individual products based on understanding the energy balance and the meaning of satiety.In the present work, the perceptions that consumers have of the word “satiating” and of different protein-based dishes were investigated in two populations (100 subjects related to the field of food science and technology and 100 unrelated to it). The Word Association (WA) technique was used, asking the consumers for the first four words that came into their mind when they thought of “satiating food”. This was followed by a Free Listing (FL) exercise that asked them to list four satiating food items. They also completed a Nutritional Knowledge Questionnaire. To evaluate the consumers' perception of the expected satiating capacity of different protein-based meals, they were shown eight photographs of equicaloric dishes composed of one piece of protein (beef, pork, chicken or fish) and one of two different side vegetables (salad or boiled potatoes). The expected satiety scores ranked fish last among the protein foods and potatoes last among the side vegetables. The results indicated that “satiating” food was related more with the immediate sensation of “stomach full” than with the cessation of hunger. This was reinforced by the mention of negative sensations of discomfort after a copious meal. Hearty dishes and meat were the meals most associated with satiating food items.     

In vitro and In vivo studies on intragastric soya protein–polysaccharide gels in a beverage matrix

Intragastric gelation is a mechanism whereby a consumed liquid food gels under the acidic gastric condition. It was hypothesised that intragastric gelation would result in satiety due to delayed gastric emptying. Three treatment beverages that is soya protein isolate (SPI) with λ‐carrageenan (SPI‐LC; high viscosity, gelling), guar gum (SPI‐GG; high viscosity) and no polysaccharide (SPI; low viscosity) were given to twenty participants in a randomised 3 × 3 double‐blind within‐subject crossover design trial and asked to rate their hunger and fullness scores (visual analogue scale; VAS) before and up to 60 min after consumption of the beverage. Results show that there were no significant effects on hunger, fullness and energy intake after consuming the SPI‐LC (gelling) beverage compared to the SPI‐GG beverage, but did evoke weak satiety signals up to 20 min after consumption when compared to the control (low‐viscosity) SPI beverage. Therefore, intragastric gelation does not result in satiety in this study.     

Dynamic aspects of liking: post-prandial persistence of sensory specific satiety

The time dependence of the liking of foodstuffs was investigated in a study with 25 subjects, consisting of three parts: (1) on day one, a sensory specific satiety study, which was extended until 125 min after consumption; (2) on days two to seven, a repeated in home taste and evaluation study; (3) on day eight, a second sensory specific satiety study as in 1.In parts 1 and 3, subjects were asked to eat either cheese biscuits or pears in light syrup to satiety. The change in liking of both foodstuffs, after eating one of the two foodstuffs to satiety, was followed during 125 min. In part 2, the same subjects were asked to taste and evaluate each product at home, every day for six days.In the sensory specific satiety studies (parts 1 and 3) a significant decrease in liking was observed for the product eaten to satiety, as long as 125 min after consuming that product to satiety. For both products contrast effects were observed: the liking of the uneaten product increased after eating the other product to satiety, while the liking of the eaten product decreased. This contrast effect lasted longer after eating cheese biscuits to satiety, than after eating pears to satiety.In the in home taste and evaluation study, a significant and linear decrease in liking was observed for both products during six days. There was a significant effect (p < 0.05) of eating cheese biscuits to satiety in the sensory specific satiety study on day 1, on the liking ratings of the in home consumption study. No such effect was observed for the pears.The results indicate that sensory specific satiety is relatively strong for more than 2 h after consumption and can have effects on liking ratings for more than 24 h. These effects were different for the products tested. Based on these results, we suggest that combining eating a product to satiety and in home evaluation over several days, could possibly be useful as an accelerated method to predict changes in liking upon repeated consumption.     

Exploring relationships between satiation,perceived satiety and plant-based snack food features

We aimed to identify relations between satiation and subsequent satiety for six plant-based foods (apple, avocado, banana, carrot, chick pea and macadamia) using a panel of ten healthy participants and a complete crossover randomised design. Food was served as a mid-morning snack ad libitum over 20 min until participants were comfortably full, and subsequent satiety was monitored for up to 180 min. Carrot and macadamia had significantly higher perceived fullness during eating, but also significantly lower perceived satiety per gram than other foods. Food energy factors had no strong relationship with perceived fullness, but were significantly positively correlated with satiety. Mastication number had significant effects on both perceived fullness (negative) and satiety (positive). This pilot study showed that plant food factors affecting perceived fullness during eating and subsequent satiety are different, and suggests how portion control through satiation for different plant-based snacks may influence both energy intake and subsequent satiety.     

How sweetness intensity and thickness of an oral nutritional supplement affects intake and satiety

Oral nutritional supplements (ONS) can be used to improve the nutritional status of malnourished patients, but their effectiveness depends on adequate intake. This is not always achieved due to the disliked flavour and satiating properties of ONS. The aim of this study was to investigate the effect of sweetness intensity and thickness on intake and sensory sequential profile of an ONS. It was hypothesized that lower sweetness intensity and thickness would decrease oro-sensory stimulation and satiety, improve the sensory profile, and thus, improve ONS intake.The effect of sweetness intensity and thickness on intake and satiety was investigated using a 2 × 2 design (low-high-sweetness and thin/thick). Participants (n = 36) consumed each ONS to satiation. Each ONS was identical in macronutrient and calorie content. Appetite and thirst were measured throughout the morning of the test. Additionally, an expert sensory panel (n = 11), performed a sensory sequential profile of each ONS.No effect of sweetness intensity was found. Results showed that 33% more of the thin, compared to thick, ONS was consumed, without affecting satiety. Furthermore, mouth-drying first increased, up to a consumption volume of 300 ml, and then decreased, independent of sweetness intensity and thickness.In conclusion, this study showed that an ONS with lower thickness increased intake in healthy adults, without affecting satiety. This implies that, for ONS, attention should not be solely focused on nutritional content. Instead, a sensory-nutrition approach is recommended that balances nutritional content with oro-sensory cues. This proof of concept should be further investigated with malnourished older adults.     

Pleasantness,emotions and perceptions induced by coffee beverage experience depend on the consumption motivation (hedonic or utilitarian)

Motivations to consume a given food or drink differ across consumers. For instance, coffee drinking can be motivated by sensory enjoyment (hedonic motivation) or by stimulation (functional motivation). Today it remains unknown how hedonic vs. utilitarian motivations impact consumer–product interaction. The objective of the present research was to study the impact of both motivations on consumer responses (i.e. pleasantness, emotions, and importance and satisfaction for each of the five senses) during the entire experience of a coffee beverage. Sixty participants drinking coffee beverage either for sensory enjoyment (SENS, n = 30) or to be stimulated (STIM, n = 30) were recruited. Four moments of the product experience were considered: water heating, jar handling, cup preparation and cup drinking. Self-ratings were repeatedly performed by the participants after each moment. SENS participants depicted higher positive emotions than STIM participants and even if similar levels of pleasantness were reached after cup drinking by both groups, levels of pleasantness at water heating and jar handling moments differed. The importance and satisfaction for the different senses also changed according to the participant motivation to drink the coffee beverage. Marketing implications are discussed in terms of communication materials development to more strongly engage consumers with the product.     

Appetite,hunger, and satiety in the elderly

Food intake declines with age and the elderly frequently report a decrease in appetite. Social and physical factors as well as decreased energy expenditure may be part of the explanation for the decreased food intake; however, it is possible that changes in hunger mechanisms are also involved, but more studies similar to those conducted on thirst are needed. The consumption of a varied diet depends in part on sensory‐specific satiety, that is, the decrease in the pleasantness of a food as it is consumed. We have shown that sensory‐specific satiety changes with age such that it was absent in individuals over the age of 65 and this could be part of the explanation of why the elderly consume more monotonous diets. Additional basic studies on how aging affects the controls of food intake will suggest ways to improve the nutritional status of the elderly.     

Associations between nutritional properties of food and consumer perceptions related to weight management

Consumer perceptions of food (for example, how filling or healthy) influence eating behaviour and appetite control. Therefore approaches to understand the global nutritional attributes of foods that predict the strength of consumer perceptions are of academic and commercial interest. The current research describes the development of a flexible platform for systematically mapping the global nutritional attributes of foods (both objective and perceived) to consumer perceptions of those foods. The platform consists of a database of standardised UK food images (currently n = 300), linked to a catalogue of detailed perceptual, nutritional, sensory, cost, and psychological information (‘nutritional attributes’). The platform also incorporates demographic and psychometric questionnaires to examine the importance of nutritional attributes on consumer perceptions within or between relevant target groups. In the current study, the platform was applied to a sample of dieting and non-dieting British men and women (n = 887) to examine the global attributes of a subset of foods (n = 75) and their association with successful weight management (i.e. supportive of weight loss, weight loss maintenance or prevention of weight gain). Generalised linear models identified energy density, cost (£/kcal), perceived energy content and satiating capacity as the main nutritional attributes underlying dieters’ and non-dieters’ perception of successful weight management food. Additionally, pleasantness, and desire not to (over) eat were uniquely associated with dieters’ perception of food as good for weight management; pleasantness was positively associated with weight management and desire to eat was negatively associated with weight management. Therefore, global nutritional attributes of foods can predict and distinguish the extent consumers’ perceive a food to be related to successful weight management. This platform will be extended to increase the variety of foods and specificity of nutritional attributes in the database suitable for a range of commercial, academic or clinical research applications.     

Survival of Lactobacillus casei (LC-1) adhered to prebiotic vegetal fibers

This study evaluated the survival of Lactobacillus casei (LC-1) when adhered to four different dehydrated prebiotic fibers. After vacuum drying in oat bran with 9% β-glucan and green banana flour, LC-1 viability was 79% and 76%, respectively. Scanning electron microscopy images revealed no morphological changes in the cells adhered to these fibers, and the addition of trehalose as a cell protectant had a positive and significant effect on the survival of LC-1. At different storage temperatures, oat bran had the highest stability as well as in simulated gastrointestinal conditions, where LC-1 that adhered to the oat bran had greater viability (7.1 log CFU g^? 1) than in the free form (2.4 log CFU g^? 1). In the sensory evaluation, the probiotic oat bran added to a dairy fruit beverage was well accepted by consumers.Industrial relevanceThe diversification of food products and the growing interest in health life requires from food industry innovations and new products for this. Probiotic cultures into non-dairy products is still an innovation and a challenge to the functional food segment. The development of an oat bran with LC-1 adhered is important for the functional food industries because the probiotic can be viable during dehydration and storage at room temperature. In addition the LC-1 is protected under simulated gastrointestinal conditions without compromising sensory acceptability.     

School meal acceptance depends on the dish,student, and context

Students (n = 127) from grades 3, 6, and 8 (8–15-year-old) evaluated 13 school meals with special attention to main dishes. Hedonic ratings (1 = really bad, 7 = really good) of 1109 meals, perceived hunger prior to eating, and aspects of the eating context were rated. Attitudes to school meals and food neophobia were measured. Considerable differences were observed in responses to main dishes, soups being better accepted than casseroles or dishes served with starches. A semi-trained laboratory panel (n = 17) characterized the best liked main dishes as being recognizable by appearance, odor and flavor, and bright and colorful, while the least liked dishes were described as having fatty mouth feel and cheesy odor and flavor. Hedonic ratings of main dishes were highly correlated with overall meal ratings. The 3rd graders rated the main dishes higher than 6th and 8th graders, who perceived them as too low in spiciness and not hot enough when served. Typically, 3rd grade boys rated the meals most positively and 6th grade boys most negatively. Attitudes to school meals were more positive in 3rd graders than in higher-grade students. In regression analysis explaining 29.7% of variation, hedonic ratings of the meals were positively predicted by attitudes to school food, perceived hunger, and appropriate queuing in the canteen, and negatively predicted by food neophobia and being a 6th or 8th grader. In conclusion, sensory characteristics of main dishes greatly affect the popularity of school meals; and means to impact the negative attitude to school food in teenage would be of great use.     

Short-term appetite-reducing effects of a low-fat dairy product enriched with protein and fibre

The objectives of this work were to investigate short-term appetite-reducing effects of an innovative low-fat yogurt enriched with protein (8 g/serving) and fibre (2.6–2.9 g/serving). Two studies were conducted using randomised cross-over designs. Healthy women consumed a mid-morning snack consisting of either the test or the control yogurt product (Study 1, n = 24: iso-energetic, not iso-weight conditions; Study 2, n = 121: iso-weight, not iso-energetic conditions) under laboratory conditions. Subjective appetite ratings (of hunger, fullness, desire to eat and prospective consumption) were recorded throughout the morning; sensory and hedonic ratings were also collected. In Study 2, two hours after consumption of the dairy snack, subsequent food intake at lunch was also measured. The test product reduced subjective appetite compared to the control (all ratings, P < 0.05). Energy intake at lunch was reduced by 274 kJ after the test compared to the control (P < 0.001). These two studies demonstrated that a low-fat dairy product enriched with protein and fibre can significantly reduce short-term appetite.     

Satiety and consumers' perceptions: What opinions do Argentinian and Brazilian people have about yogurt fortified with dairy and legume proteins?

This study (1) evaluated the perceptions of Argentinian and Brazilian consumers regarding yogurt fortified with dairy proteins, legume proteins, or a combination of both, and (2) determined the satiety expectations of these foods as well as the consumers' intentions to taste and purchase protein-fortified yogurt. A total of 298 Argentinian and 100 Brazilian participants completed an online survey for this study. The free word association technique was used to investigate their perceptions about “satiety” as a verbal stimulus and 6 concepts of yogurt as visual/verbal stimuli (yogurt, set yogurt, skim set yogurt, skim set yogurt with a high content of dairy proteins, skim set yogurt with a high content of legume proteins, and skim set yogurt with a mix of dairy and legume proteins). The expected satiation and intentions to taste or purchase were evaluated using categorical scales. Regardless of their cultural background, participants from both countries expressed similar associations with the stimuli presented. Yogurt and set yogurt were associated with consumption occasions, sensory characteristics, liking, and foods, whereas skim yogurt was associated with diet food. Products fortified with proteins were associated with healthy foods, regardless of the protein source, and they yielded the highest rates for expected satiation. Brazilian participants were more likely to taste the food with a combination of proteins; however, participants from both countries were indifferent to purchasing the product. Important characteristics in the design and marketing of these products were pleasant sensations, such as “fullness,” “satisfied,” and snacks to eat “on the go,” and the vegetarian consumers' segment. The combination with fruits or cereals, creaminess, and vanilla flavor should also be considered. The study findings could have implications for the dairy industry when designing yogurt fortified with proteins and communicating the nutritional and wholesome properties of these products.     

Successful development of satiety enhancing food products: towards a multidisciplinary agenda of research challenges

In the context of increasing prevalence of overweight and obesity in societies worldwide, enhancing the satiating capacity of foods may help people control their energy intake and weight. This requires an integrated approach between various food-related disciplines. By structuring this approach around the new product development process, this paper aims to present the contours of such an integrative approach by going through the current state of the art around satiety enhancing foods. It portrays actual food choice as the end result of a complex interaction between internal satiety signals, other food benefits, and environmental cues. Three interrelated routes to satiating enhancement are to change the food composition to develop stronger physiological satiation and satiety signals, anticipate and build on smart external stimuli at the moment of purchase and consumption, and improve palatability and acceptance of satiety enhanced foods. Key research challenges in achieving these routes in the field of nutrition, food technology, consumer, marketing, and communication are outlined.     

Is there a fit in cognitive and sensory evaluation of yogurt? The moderating role of nutrition training

Food selection at a particular occasion is guided by properties of the food itself (sensory or intrinsic properties), but also by the information provided with the food, for example, packaging information (extrinsic properties). We compared preference responses of 71 consumers with a considerable type 2 diabetes risk, who had undergone nutrition counseling in a prevention program, in sensory assessments and product evaluation integrated into Adaptive Conjoint Analysis with the response of a healthy control group (n = 101). Vanilla yogurt, varied in composition (fat content, sugar content, flavor intensity) and packaging information (fat content, sugar content, flavor intensity), was used as stimulus material. Both groups of consumers preferred yogurt with a higher fat content on the basis of sensory evaluation, but rejected products with a higher fat content (10 g/100 g) when this information was available on the package. The degree of rejection was significantly higher for the high risk group. Whereas both groups preferred reduced-sugar yogurt on the basis of declaration, preferences towards the less sweet product were only observed for the high risk group.     

Development and Quality Evaluation of a Non-Alcoholic Beverage from Cocoyam (Xanthosoma sagittifolium and Colocasia esculenta)

Cocoyam tubers were processed into non-alcoholic beverage, flavoured with 0.5% and 1.0% extracts of ginger and alligator pepper respectively. Two varieties of cocoyam, namely Colocasia esculenta and Xanthosoma sagittifolium were used. The purpose of this study is to develop an acceptable flavoured non alcoholic beverage from cocoyam and thereby increase the utilization of this under-utilized crop. The proximate, vitamins C and A, mineral content, microbial and sensory evaluation were conducted on the products to assess the highest preference. Values for pH ranged from 3.00 to 3.86 and the total titratable acidity (TTA) from 0.50 – 0.82 with ginger flavoured samples rated higher than that of alligator pepper. Total solids varied significantly and ranged from 5.00 – 6.02% with alligator pepper samples being higher than ginger. Vitamin C content ranged from 1.02 – 1.98 × 10⁻⁴ mg/100 g while vitamin A content ranged from 6.04 to 14.41 μg/100 g with ginger flavoured samples having higher vitamin C and A than the alligator flavoured ones. The minerals evaluated showed a decreasing trends with increase in the concentration of each spice. The sensory results showed that significant differences (p < 0.05) existed between the different flavoured samples and not between varieties. The microbial analysis showed that the cocoyam non-alcoholic beverage is safe for human consumption. Generally, the beverage had good consumer preference with the 0.5% ginger flavoured being the most preferred.