Fracture properties of foods: Experimental considerations and applications to mastication

Correlation between Depth of the Curve of Spee and Some Specific Malocclusion Characteristics in a Population from Sibiu County, Romania-A Cross-Sectional Study

Background: This study aimed to investigate the relationship between the Curve of Spee (COS) depth and malocclusion characteristics in a population from Sibiu County, Romania. The research sought to understand how the COS's anatomical dimensions correlate with different classes of malocclusion and the position of the frontal teeth. Methods: A total of 265 participants from the Dentistry Ambulatory of the Military Hospital of Sibiu were included in this study. It employed digital intraoral scanning technology to measure the COS, overjet, and overbite, with malocclusion classification. Statistical analyses, including correlation and regression, were conducted to examine the relationships between COS depth, frontal teeth position, and malocclusion characteristics. Results: The average COS depth measured was 1.0564 mm, presenting variability when compared to existing literature. Most of the study participants had Class I malocclusion. A significant positive correlation between COS depth and overjet was identified, with no notable gender-based differences in these occlusal parameters. Conclusions: The findings affirm the integral role of COS in occlusal dynamics and malocclusion diagnosis. The COS measurement of a mean of 1.0564 mm, when compared to other results emphasizes the differences in occlusal curvature among various populations. The results contribute to a refined understanding of occlusal relationships, supporting the need for personalized orthodontic and prosthetic treatments based on precise anatomical measurements.

Bioactives and Technological Quality of Functional Biscuits Containing Flour and Liquid Extracts from Broccoli By-Products

Broccoli by-products are an important source of health-promoting bioactive compounds, although they are generally underutilized. This study aimed to valorize non-compliant broccoli florets by transforming them into functional ingredients for biscuit formulation. A broccoli flour and three water/ethanol extracts (100:0, 75:25, 50:50; v/v) were obtained. The rheological properties and the content of bioactive compounds of the functional ingredients and biscuits were evaluated. The 50:50 hydroalcoholic extract was the richest in glucosinolates (9749 µg·g-1 DW); however, the addition of a small amount strongly affected dough workability. The enrichment with 10% broccoli flour resulted the best formulation in terms of workability and color compared to the other enriched biscuits. The food matrix also contributed to protecting bioactive compounds from thermal degradation, leading to the highest total glucosinolate (33 µg·g-1 DW), carotenoid (46 µg·g-1 DW), and phenol (1.9 mg GAE·g-1 DW) contents being present in the final biscuit. Therefore, broccoli flour is a promising ingredient for innovative healthy bakery goods. Hydroalcoholic extracts could be valuable ingredients for liquid or semi-solid food formulation.

A breakage index for characterizing in vitro nut fragmentation and predicting human oral fragmentation

Breakage of food influences eating experience and sensory perception. The aims of the study were to identify an appropriate breakage index and to develop an in vitro method for predicting the ease of oral breakage of nuts. Kernels of five types of nuts were fragmented in vitro using a texture analyzer and 12 subjects therefore performed molar bites. In addition, peanuts were differently roasted (over 0, 15, 25, and 35 min) to vary texture within the same nut type. Projected particle areas were determined using imaging. Two Breakage Indices were compared (1) BI-I, the difference, after and before fragmentation, in square root values of ratios between total projected area and volume [Agrawal et al., 1997, Archives of Oral Biology, 42(1), 1-9], and (2) BI-II, the ratio of the total projected area after and before fragmentation. BI-II gives a stronger linear regression than BI-I between in vivo and in vitro index values for different types of nuts; Pearson's r = 0.834 versus 0.499 (12 subjects with all data pooled). Using BI-II, a subject's regression result in fragmentation tests with differently roasted peanuts was as strong as when testing different nut types: Pearson's r = 0.984 versus 0.964. Since the range of the in vitro BI-II values was 5.5 times smaller in the peanut tests, the finding of a similarly strong regression indicates a high sensitivity of BI-II to detect differences in food texture. BI-II is useful for food industry to determine how easily solid foods break down and thereby compare the potential of flavor release between foods during chewing.

Effect of the incorporation of pregelatinized cassava starch on the physicochemical, textural, and acoustic characteristics of baked snacks

Almost all the dehydrated cassava puree is pregelatinized cassava starch (PCS). Its potential application in food would add variety. But food characteristics vary depending on the raw materials used. We examined how the structure of snacks changed when PCS was used instead of flour in terms of porosity, instrumental textural parameters, and acoustic parameters and compare them to commercial crackers. The volume of air was unaffected by the substitution. However, substitution did reduce thickness and alter the number, size, and wall firmness of pores, as well as their distribution and shape, which raise the values of firmness, fracturability, hardness, and fragility, though not linearly. The partial substitutions and the control did not exhibit any appreciable differences in the acoustic parameters. The total replacement sample was noisier and maintained a wide variety of sounds. The PCS vitreous state is primarily responsible for structure changes, but other elements, such as processing conditions, contribute to differences in comparison to the commercial samples. The porosity of commercial samples was lower than that of the elaborated samples. Texturally, it led to lower fracturability and greater fragility (less mm until fracture and fewer force peaks). The elaborated samples were all louder than the commercials. Although sensory analysis is required to classify a food as crunchy, the physicochemical changes caused by the substitution and their impact on the structure's behavior were established. Each textural parameter cannot determine whether the food is crunchy, crispy, or friable on its own; an analysis that incorporates all the characteristics is required. Supplement Material. PRACTICAL APPLICATION: This study demonstrates that pregelatinized cassava flour can be used to partially or completely replace wheat flour in baked snacks. Although textural differences were noted, these alterations were acceptable for products with a similar market niche. These findings might be used in the food business, notably by companies aiming to offer baked snack choices that are not made with standard wheat flour.

In vitro digestion models for the design of safe and nutritious foods

Responsible development of future foods requires in depth understanding of food digestion in the human body based on robust research models, ranging from in vitro models to randomized controlled human trials. This chapter overviews fundamental aspects of food digestion, namely bioaccessibility and bioavailability, and models mirroring gastric, intestinal, and colonic conditions. Second, the chapter demonstrates the potential of in vitro digestion models to help screen adverse effects of food additives, such as Titanium dioxide or carrageenan, or underpin the determinants of macro- and micronutrient digestion in different strata of the population, for example digestion of emulsions. Such efforts support rationalized design of functional foods, such as infant formulae, cheese, cereals and biscuits which are validated in vivo or in randomized controlled trials.

Application of a Tensile Test Method to Identify the Ductile-Brittle Transition of Caramel

During cutting of foods, tensile stresses in front of the blade are responsible for the separation of the material. Therefore, tensile tests can be helpful to gain knowledge on deformation properties related to pre-fracture cutting behavior as well as on phenomena in the fracture zone, which are velocity-dependent in viscoelastic materials. The aim of this work was to apply a tensile test method for model caramels to investigate their behavior and to identify conditions where the ductile-brittle transition occurs. After executing pre-trials, tensile velocity, caramel moisture, and temperature were the parameters that were varied for this purpose. In general, increasing velocity, decreasing temperature, and decreasing moisture resulted in a stiffer response and caused a shift from a ductile to a more brittle behavior, attributable to reduced viscous contributions to the material and longer relaxation times. Fracture strain was notably lower than the maximum plastic elongation in the ductile case, but we observed equalization close to the ductile-brittle transition point for our material. This study serves as basis for an in-depth research on the complex deformation and fracture phenomena during cutting of viscoelastic food systems, including numerical modeling.

Convection Drying Influence on Thermo-Physical Properties, Bioactive Substances, Color and Texture Profile of Red Pepper (Capsicum Spp)

This work aimed to study the effect of convection drying on bioactive substances and on the texture profile of red pepper. Four mathematical models were used to model the drying kinetics, as a function of the temperature and the thickness of slices. These models are largely in agreement with experimental data. Effective diffusivity, Arrhenius constant, activation energy and thermal properties changed with temperature of dry process. The two varieties of pepper used in this work demonstrated a very high degree of spiciness (144799.37-160899.37 SU). This property is related to the high contents of capsaicin (39.60-44.01 mg/g) and dihydrocapsaicin (32.33-35.95 mg/g). Our results revealed that brittleness, hardness 1 and 2, firmness, chewiness, gumminess appearance and Young’s modulus are very important attributes in determining the textural profile of dried red pepper. Also, drying causes a strong degradation of natural pigments of red pepper and consequently decreases attractiveness of the texture profile. To avoid that, red pepper should be pretreated before the application of hot air drying.

A Review of In Vitro Methods for Measuring the Glycemic Index of Single Foods: Understanding the Interaction of Mass Transfer and Reaction Engineering by Dimensional Analysis

The Glycemic Index (GI) has been described by an official method ISO (International Organization for Standardization) 26642:2010 for labeling purposes. The development of in vitro methods for GI measurement has faced significant challenges. Mass transfer and reaction engineering theory may assist in providing a quantitative understanding of in vitro starch digestion and glycemic response from an engineering point of view. We suggest that in vitro GI measurements should consider the mouth and the stomach in terms of fluid mechanics, mass transfer, length scale changes, and food-solvent reactions, and might consider a significant role for the intestine as an absorption system for the glucose that is generated before the intestine. Applying mass transfer and reaction engineering theory may be useful to understand quantitative studies of in vitro GI measurements. The relative importance of reactions and mass-transfer has been estimated from literature measurements through estimating the Damköhler numbers (Da), and the values estimated of this dimensionless group (0.04–2.9) suggest that both mass transfer and chemical reaction are important aspects to consider.

Ease of mastication index-Quantification of mastication effort using quality function deployment

An effort required to masticate a bite of food seems important for a broad group of consumers considering many foodstuffs. Consumers with specific needs (elderly, people with impaired oral functioning) are also interested in ease of mastication. Besides understanding the relationships between mastication and sensory perception, a better insight into foodstuffs' mastication effort is needed to gain vital information when choosing the food and judging its quality. However, there is not much work describing the quantification of mastication effort as a quality grade. Within this research, we: (a) analyzed consumers' demands toward mastication attributes, (b) examined mastication, mechanical, and sensory parameters for nine foodstuffs (meat and dairy products), and (c) developed a quality function deployment model that connects consumers' demands with a multidimensional technical scale, enabling mastication effort quantification through a novel "ease of mastication index" (EMI). As a single-value quality score, EMI answers how much effort must be applied to masticate certain foodstuff. It is a left-sided index (it can have only positive values up to EMI = 1), having the maximal value for creamy cheese (0.96) and minimal (0.40) for fermented sausage in the present study, meaning the latter was the most difficult case study product for mastication. This study's practical application may be seen in the proposed model usage for foodstuffs research and development, bearing in mind ease of mastication. EMI may play an essential role as a novel quality indicator that can be considered crucial for broad and specific consumer groups.

Development of a Caramel-Based Viscoelastic Reference Material for Cutting Tests at Different Rates

Cutting speed plays a crucial role for the behavior during and the final quality of viscoelastic foods after cutting and is, in industrial applications, usually adjusted on an empirical basis. Although previous studies investigated the interplay between the time-dependent properties and cutting behavior of model systems on an elastomer basis, there is still a need to elaborate such cause-effect relations for real foods. The aim of this study was to establish a reproducible manufacture of model caramels on a laboratory scale and to investigate the influence of the compositional parameters, moisture, and solid fat content, as well as cutting speed, on cutting behavior. It was possible to visualize ductile-brittle transitions in cutting force profiles, with an increase in cutting speed resulting in effects similar to that induced by a decreasing moisture content or an increasing solid fat content. Quantitatively, the progression of both maximum force and cutting energy reversed when cutting speed increased and composition changed in favor of a more brittle behavior. This work provides the basis for further research on distinct loading phenomena observed during the cutting of foods and for numerical modeling of the cutting process.

Modelling Volume Change and Deformation in Food Products/Processes: An Overview

Volume change and large deformation occur in different solid and semi-solid foods during processing, e.g., shrinkage of fruits and vegetables during drying and of meat during cooking, swelling of grains during hydration, and expansion of dough during baking and of snacks during extrusion and puffing. In addition, food is broken down during oral processing. Such phenomena are the result of complex and dynamic relationships between composition and structure of foods, and driving forces established by processes and operating conditions. In particular, water plays a key role as plasticizer, strongly influencing the state of amorphous materials via the glass transition and, thus, their mechanical properties. Therefore, it is important to improve the understanding about these complex phenomena and to develop useful prediction tools. For this aim, different modelling approaches have been applied in the food engineering field. The objective of this article is to provide a general (non-systematic) review of recent (2005-2021) and relevant works regarding the modelling and simulation of volume change and large deformation in various food products/processes. Empirical- and physics-based models are considered, as well as different driving forces for deformation, in order to identify common bottlenecks and challenges in food engineering applications.

Mechanical cell disruption of mustard bran suspensions for improved dispersion properties and protein release

Mustard bran, a by-product of mustard production, is still rich in valuable compounds. The high-pressure homogenization treatment was tested as a mechanical cell disruption (MCD) technique to unlock valuable intracellular compounds. An aqueous suspension of mustard bran was treated by shear mixing, followed by high-pressure homogenization at different pressure levels (50-150 MPa) and number of passes (1-10), and using different homogenizing systems. The moderate-intensity treatment (up to 100 MPa and 3 passes) can deliver significant changes in the mustard bran suspension, inducing (a) a more homogeneous and smooth appearance due to the disruption of individual cells, (b) a better structuring ability in the suspension, through the increase in viscosity and storage and loss moduli G' and G'', as well as (c) a remarkable enhancement of protein release, up to 72% of total proteins. The controlling factor in the extent of MCD was found to be the specific energy transferred to the mustard bran suspensions, whereas no significant differences were recorded when varying the homogenization system. The MCD process of mustard bran, based on its physical treatments using only water as a suspension medium, can be regarded as a safe, clean and environmentally friendly technology platform, which contributes to reaching the zero-waste concept by transforming agro-food by-products into value-added ingredients, with enhanced functionality and bioactive content.

Understanding the interplay between food structure, intestinal bacterial fermentation and appetite control

Epidemiological and clinical evidence highlight the benefit of dietary fibre consumption on body weight. This benefit is partly attributed to the interaction of dietary fibre with the gut microbiota. Dietary fibre possesses a complex food structure which resists digestion in the upper gut and therefore reaches the distal gut where it becomes available for bacterial fermentation. This process yields SCFA which stimulate the release of appetite-suppressing hormones glucagon-like peptide-1 and peptide YY. Food structures can further enhance the delivery of fermentable substrates to the distal gut by protecting the intracellular nutrients during upper gastrointestinal digestion. Domestic and industrial processing can disturb these food structures that act like barriers towards digestive enzymes. This leads to more digestible products that are better absorbed in the upper gut. As a result, less resistant material (fibre) and intracellular nutrients may reach the distal gut, thus reducing substrates for bacterial fermentation and its subsequent benefits on the host metabolism including appetite suppression. Understanding this link is essential for the design of diets and food products that can promote appetite suppression and act as a successful strategy towards obesity management. This article reviews the current evidence in the interplay between food structure, bacterial fermentation and appetite control.

Plant Cell Walls: Impact on Nutrient Bioaccessibility and Digestibility

Cell walls are important structural components of plants, affecting both the bioaccessibility and subsequent digestibility of the nutrients that plant-based foods contain. These supramolecular structures are composed of complex heterogeneous networks primarily consisting of cellulose, and hemicellulosic and pectic polysaccharides. The composition and organization of these different polysaccharides vary depending on the type of plant tissue, imparting them with specific physicochemical properties. These properties dictate how the cell walls behave in the human gastrointestinal tract, and how amenable they are to digestion, thereby modulating nutrient release from the plant tissue. This short narrative review presents an overview of our current knowledge on cell walls and how they impact nutrient bioaccessibility and digestibility. Some of the most relevant methods currently used to characterize the food matrix and the cell walls are also described.

Computer simulations of food oral processing to engineer teeth cleaning

Oral biofilm accumulation in pets is a growing concern. It is desirable to address this problem via non-invasive teeth cleaning techniques, such as through friction between teeth and food during chewing. Therefore, pet food design tools are needed towards optimising cleaning efficacy. Developing such tools is challenging, as several parameters affecting teeth cleaning should be considered: the food’s complex mechanical response, the contacting surfaces topology as well as the wide range of masticatory and anatomical characteristics amongst breeds. We show that Finite Element (FE) models can efficiently account for all these parameters, through the simulation of food deformation and fracture during the first bite. This reduces the need for time consuming and costly in-vivo or in-vitro trials. Our in-silico model is validated through in-vitro tests, demonstrating that the initial oral processing stage can be engineered through computers with high fidelity.

Oral care based foods are of great interest for increasing the dental health of animals. Here, the authors report on computer simulations to optimise the texture and geometry of food in order to maximise tooth abrasion and enhance cleaning efficiency.

Fatty acid bioaccessibility and structural breakdown fromin vitrodigestion of almond particles

In vitrogastric digestion of almond particles using a model with simulated peristaltic contractions resulted in particle size reduction and higher fatty acid bioaccessibility thanin vitrodigestion using a model that lacked peristaltic contractions.