Internal preference mapping and the issue of satiety

Internal preference mapping (IPM) and Landscape Segmentation Analysis® (LSA) are two techniques broadly used to unfold consumers’ overall product liking ratings and create spatial maps that will provide further insights on consumers’ preferences. IPM is based on a vector model while LSA involves an ideal point model. Through a simulation and the analysis of 27 market research data sets, it is shown that IPM consistently creates a hedonic dimension that prevents the identification of satiety prone attributes (intensities higher or lower than a optimal level being disliked by the consumers) on that dimension. As a result, subsequent steps taken upon generating an IPM map such as the investigation of drivers of liking, population segmentation and the estimation of optimal product profiles have also a strong likelihood of resulting in distorted results, the level of distortion being dependent on the actual configuration of the underlying structure that IPM tried to uncover. It is also shown that a technique based on ideal points such as LSA does not exhibit this systematic artifact when unfolding liking data. Consequently, sensory scientists and market researchers should use caution when interpreting and using results issued from an internal preference mapping analysis.     

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.     

The effect of alginates on in vitro gastric digestion of particulated whey protein

The aim of the study was to investigate how microparticulated and nanoparticulated whey proteins mixed with alginate respond to simulated in vitro gastric digestion conditions at pH 3.0. Initially, particle size distributions and zeta potential were measured in all mixtures at pH 3.0. Particle size distributions as well as SDS‐PAGE were used to investigate the rate of protein degradation by pepsin during simulated in vitro gastric digestion. The complexation of nanoparticulated and microparticulated whey protein with alginates causes formation of insoluble and soluble complexes, which can resist pepsin degradation to a different degree. These results highlight the potential of developing new food products, which can enhance satiety.     

影响饱腹感的成分及其生理功能的研究进展

摄食是是影响人们在短期内的能量获取的重要因素。过度的食物摄入造成人体非必需能量增加,引发肥胖、糖尿病、冠心病等疾病。为改善营养过量摄入现状,人们通过产生自身饱腹感来降低食物摄入量。有研究表明,含有膳食纤维,淀粉,蛋白质的食物摄入后会产生强烈饱腹感,能够有效减少能量摄入,但是人们却对其中的机制知之甚少。本文主要对人体饱腹感产生机理、产生饱腹感的物质种类(膳食纤维,淀粉,蛋白质)及其生理功能进行论述,旨在为人类健康饮食和预防疾病的研究提供思路。     

Characterization of in-vitro gel performance of novel MC with respect to the suitability for satiety applications

Rheological properties of aqueous solutions of a novel methyl cellulose has been compared to the performance of a conventional methyl cellulose. Gel formation of these materials is trigged only by increased temperatures. The low gelation temperature of the novel methyl cellulose enables this material to gel at body temperature. Compression measurements of the gels at various concentrations were performed and the investigated gel strength could be fitted according to an exponential equitation. The comparison to alginate as a known gel forming agent by acidification and known as satiety inducing agent showed comparable gel strength at 37 °C. Therefore, a potential of the novel methyl cellulose for human weight management applications has been identified. Gel formation in the human stomach could lead to a satiety effect.     

Investigation of the behaviour of chitosan microparticles as pH responsive hydrogels in the gastro-intestinal tract using magnetic resonance imaging

The objective of this research was to determine whether chitosan microparticles could be developed as potential satiety enhancing ingredients by investigating their swelling behaviour in the gastro-intestinal tract using magnetic resonance imaging (MRI). Previous work undertaken using a covalently cross-linked composite of chitosan and bovine serum albumin (BSA) showed this system swells in gastric conditions in vitro (Butler, Clark, & Adams, 2006). This paper describes the preparation and characterisation of chitosan/BSA microparticles cross-linked using 25 mM and 100 mM glutaraldehyde (GDA). 1.5% chitosan/15% BSA microparticles cross-linked with 25 mM GDA swell by 100% in simulated gastric conditions. We found an experimental correlation between the transverse NMR relaxation time, T₂, and swelling of the microparticles in vitro. Our study of four volunteers showed swelling of these microparticles in the human stomach, observed from increases in T₂ of the microparticles using non-invasive MRI. As such, our initial results, with 4 volunteers, suggest that this system could be used as a potential satiety enhancing agent in vivo as we would expect it to provide gastric distension due to swelling at low pH. Further studies with more volunteers would be necessary to confirm our initial findings.     

Control of lipase digestibility of emulsified lipids by encapsulation within calcium alginate beads

Structured delivery systems, fabricated from natural lipids and polymers, are finding increasing use to improve the oral bioavailability of poorly water-soluble drugs and nutraceuticals, as well as to control the release of lipophilic bioactive molecules within the human gastrointestinal tract. This study focused on the development of filled hydrogel particles to control the digestion and release of encapsulated lipids. These filled hydrogel particles were fabricated by trapping sub-micron lipid droplets within calcium alginate beads. These particles remained intact when the pH was varied from 1 to 7, but exhibited some shrinkage at pH 1 and 2. The free fatty acids released from the filled hydrogel particles after addition of pancreatic lipase were monitored using a pH-stat in vitro digestion model. Encapsulation of lipid droplets within calcium alginate beads (d = 2.4 mm) reduced the free fatty acids released from around 100% to less than 12% after 120 min. The rate and extent of lipid digestion increased with decreasing bead size (from 3.4 to 0.8 mm), decreasing degree of cross-linking (i.e., lower calcium or alginate concentrations), and decreasing triglyceride molecular weight (i.e., tributyrin > MCT ≈ corn oil). These results have important implications for the design of delivery systems to protect and release lipophilic bioactive components within the human body, as well as to modulate satiety/satiation by controlling the rate of lipid digestibility.     

Different tastants and low-caloric sweeteners induce differential effects on the release of satiety hormones

Recent studies have found different types of taste receptors located along the intestine. However, the effect of tastants, and in particular sweet tastants, on satiety hormone release is still unknown.     

Review of techniques to manufacture micro-hydrogel particles for the food industry and their applications

Microgels are ‘soft’ microscopic cross-linked polymeric particles that are being increasingly exploited in a variety of industries for rheology control, encapsulation and targeted delivery. They are valued because of the ability to tune their functionality to address specific applications in oil recovery, coatings, drug delivery, cosmetics, personal care and foods. Food microgels are typically biopolymer hydrogels in the form of microspheres, nanospheres (also called nanogels), spheroids and fibres. The utilisation of engineered microgels in foods has so far been limited, despite their great potential to address several needs in the food industry, including: satiety control, encapsulation of phytonutrients and prebiotics, texture control for healthier food formulations (e.g. reduced fat products), and targeting delivery to specific areas in the digestive tract. We review the scientific and patent literature on the utilisation and manufacturing methods for producing microgels with an emphasis on micro-hydrogels for food applications.