Food Oral Processing and Tribology: Instrumental Approaches and Emerging Applications

Review of formation mechanisms and quality regulation of chewiness in staple foods: Rice, noodles, potatoes and bread

Staple foods serve as vital nutrient sources for the human body, and chewiness is an essential aspect of food texture. Age, specific preferences, and diminished eating functions have broadened the chewiness requirements for staple foods. Therefore, comprehending the formation mechanism of chewiness in staple foods and exploring approaches to modulate it becomes imperative. This article reviewed the formation mechanisms and quality control methods for chewiness in several of the most common staple foods (rice, noodles, potatoes and bread). It initially summarized the chewiness formation mechanisms under three distinct thermal processing methods: water medium, oil medium, and air medium processing. Subsequently, proposed some effective approaches for regulating chewiness based on mechanistic changes. Optimizing raw material composition, controlling processing conditions, and adopting innovative processing techniques can be utilized. Nonetheless, the precise adjustment of staple foods' chewiness remains a challenge due to their diversity and technical study limitations. Hence, further in-depth exploration of chewiness across different staple foods is warranted.

A Review of In Vitro and In Silico Swallowing Simulators: Design and Applications

Swallowing is a primary and complex behaviour that transports food and drink from the oral cavity, through the pharynx and oesophagus, into the stomach at an appropriate rate and speed. To understand this sophisticated behaviour, a tremendous amount of research has been carried out by utilising the in vivo approach, which is often challenging to perform, poses a risk to the subjects if interventions are undertaken and are seldom able to control for confounding factors. In contrast, in silico (computational) and in vitro (instrumental) methods offer an alternate insight into the process of the human swallowing system. However, the appropriateness of the design and application of these methods have not been formally evaluated. The purpose of this review is to investigate and evaluate the state of the art of in vitro and in silico swallowing simulators, focusing on the evaluation of their mechanical or computational designs in comparison to the corresponding swallowing mechanisms during various phases of swallowing (oral phase, pharyngeal phase and esophageal phase). Additionally, the potential of the simulators is also discussed in various areas of applications, including the study of swallowing impairments, swallowing medications, food process design and dysphagia management. We also address current limitations and recommendations for the future development of existing simulators.

Food authentication, current issues, analytical techniques, and future challenges: A comprehensive review

Food authentication and contamination are significant concerns, especially for consumers with unique nutritional, cultural, lifestyle, and religious needs. Food authenticity involves identifying food contamination for many purposes, such as adherence to religious beliefs, safeguarding health, and consuming sanitary and organic food products. This review article examines the issues related to food authentication and food fraud in recent periods. Furthermore, the development and innovations in analytical techniques employed to authenticate various food products are comprehensively focused. Food products derived from animals are susceptible to deceptive practices, which can undermine customer confidence and pose potential health hazards due to the transmission of diseases from animals to humans. Therefore, it is necessary to employ suitable and robust analytical techniques for complex and high-risk animal-derived goods, in which molecular biomarker-based (genomics, proteomics, and metabolomics) techniques are covered. Various analytical methods have been employed to ascertain the geographical provenance of food items that exhibit rapid response times, low cost, nondestructiveness, and condensability.

Textured soy protein with meat odor as an ingredient for improving the sensory quality of meat analog and soy burger

Even with the growing consumption of plant-based products, the consumption of soy-based products is still a limitation due to the off-flavor of soy. Thus, two studies were performed using textured soy protein (TSP) with meat odor as meat analog and as soy burger. TSP with meat odor was produced by adding thiamine (aroma precursor) to soy protein concentrate (SPC) before extrusion. Three TSP were used in each study: one without thiamine and two with thiamine but with different moisture contents of the SPC. TSP with thiamine did not affect technological or physical properties of the products. For meat analogs, the samples with thiamine showed greater odor acceptance and greater intensities of meat odor, burnt aftertaste, and aromatic in relation to the sample without thiamine, as well as lower intensity of soy odor. For soy burgers, the samples with thiamine had higher acceptances of odor and flavor and overall acceptance, and higher intensities of chicken odor and aromatic in comparison to the sample without thiamine, as well as lower intensity of soy/vegetable odor. The use of TSP with thiamine raises the sensory quality of meat analogue and soy burger, being an interesting alternative in obtaining soy-based products with lower soy odor.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-023-05875-0.

Incorporation of curcumin-loaded solid lipid nanoparticles into yogurt: Tribo-rheological properties and dynamic in vitro digestion

The incorporation of nanostructures loaded with bioactive compounds into food matrices is a promising approach to develop new functional foods with improved nutritional, health profiles and good sensorial properties. The rheological and tribological properties of yogurt enriched with curcumin-loaded solid lipid nanoparticles (SLN) were evaluated. Also, the TCA solubility index, the bioaccessibility of curcumin and cell viability were assessed after dynamic in vitro digestion. The presence of SLN in yogurt did not affect its rheological properties; however, SLN addition increased the lubrication capability of yogurt. After in vitro digestion, yogurt with added SLN (yogurt_SLN) presented a lower TCA solubility index (22 %) than the plain yogurt (39 %). The bioaccessibility and stability of curcumin were statistically similar for yogurt_SLN (30 % and 42 %, respectively) and SLN alone (20 % and 39 %, respectively). Regarding cell viability results, the intestinal digesta filtrates of both controls (i.e., SLN alone and plain yogurt) did not affect significantly the cell viability, while the yogurt_SLN presented a possible cytotoxic effect at the concentrations tested. In general, the incorporation of SLN into yogurt seemed to promote the mouthfeel of the yogurt and did not adversely affect the bioaccessibility of curcumin. However, the interaction of SLN and yogurt matrix seemed to have a cytotoxic effect after in vitro digestion, which should be further investigated. Despite that, SLN has a high potential to be used as nanostructure in a functional food as a strategy to increase the bioactive compounds' bioaccessibility.

Polysaccharide-dextrin thickened fluids for individuals with dysphagia: recent advances in flow behaviors and swallowing assessment methods

The global aging population has brought about a pressing health concern: dysphagia. To effectively address this issue, we must develop specialized diets, such as thickened fluids made with polysaccharide-dextrin (e.g., water, milk, juices, and soups), which are crucial for managing swallowing-related problems like aspiration and choking for people with dysphagia. Understanding the flow behaviors of these thickened fluids is paramount, and it enables us to establish methods for evaluating their suitability for individuals with dysphagia. This review focuses on the shear and extensional flow properties (e.g., viscosity, yield stress, and viscoelasticity) and tribology (e.g., coefficient of friction) of polysaccharide-dextrin-based thickened fluids and highlights how dextrin inclusion influences fluid flow behaviors considering molecular interactions and chain dynamics. The flow behaviors can be integrated into the development of diverse evaluation methods that assess aspects such as flow velocity, risk of aspiration, and remaining fluid volume. In this context, the key in-vivo (e.g., clinical examination and animal model), in-vitro (e.g., the Cambridge Throat), and in-silico (e.g., Hamiltonian moving particles semi-implicit) evaluation methods are summarized. In addition, we explore the potential for establishing realistic assessment methods to evaluate the swallowing performance of thickened fluids, offering promising prospects for the future.

Correlating instrumental measurements and sensory perceptions of foods with different textural properties for people with impaired oral and swallowing capabilities - A review

The rising global life expectancy has underlined the necessity of designing novel and tasty food products, suitable for seniors and people with impaired oral and swallowing functions. For developing these products, texture should be optimised from rheological, colloidal, tribological, and masticatory points of view. The current review provides an overview of different studies based on shear rheological, tribological, and in vitro mastication properties of model or real food systems intended for the elderly and/or people with swallowing dysfunctions, with special emphasis on the relation between the instrumental measurements and sensory perceptions of foods. Several works demonstrated that instrumental data from shear rheological and tribological tests complement the sensory evaluations of foods, providing useful information when designing food commodities for specific populations. Conversely, only few works correlated the instrumental data obtained from artificial mouths and/or simulated masticators with the sensory attributes generated by trained assessors. Broaden knowledge of these topics will help in formulating and adapting foods with enhanced functionalities for people with impaired oral and swallowing capabilities. Shear rheology, soft oral tribology, and simulated mastication tests are crucial in designing safe- and easy-swallowing food products.

Food biopolymer behaviors in the digestive tract: implications for nutrient delivery

Biopolymers are prevalent in both natural and processed foods, serving as thickeners, emulsifiers, and stabilizers. Although specific biopolymers are known to affect digestion, the mechanisms behind their influence on the nutrient absorption and bioavailability in processed foods are not yet fully understood. The aim of this review is to elucidate the complex interplay between biopolymers and their behavior in vivo, and to provide insights into the possible physiological consequences of their consumption. The colloidization process of biopolymer in various phases of digestion was analyzed and its impact on nutrition absorption and gastrointestinal tract was summarized. Furthermore, the review discusses the methodologies used to assess colloidization and emphasizes the need for more realistic models to overcome challenges in practical applications. By controlling macronutrient bioavailability using biopolymers, it is possible to enhance health benefits, such as improving gut health, aiding in weight management, and regulating blood sugar levels. The physiological effect of extracted biopolymers utilized in modern food structuring technology cannot be predicted solely based on their inherent functionality. It is essential to account for factors such as their initial consuming state and interactions with other food components to better understand the potential health benefits of biopolymers.

Protein-Based Fat Replacers: A Focus on Fabrication Methods and Fat-Mimic Mechanisms

The increasing occurrence of obesity and other non-communicable diseases has shifted the human diet towards reduced calorie intake. This drives the market to develop low-fat/non-fat food products with limited deterioration of textural properties. Thus, developing high-quality fat replacers which can replicate the role of fat in the food matrix is essential. Among all the established types of fat replacers, protein-based ones have shown a higher compatibility with a wide range of foods with limited contribution to the total calories, including protein isolate/concentrate, microparticles, and microgels. The approach to fabricating fat replacers varies with their types, such as thermal-mechanical treatment, anti-solvent precipitation, enzymatic hydrolysis, complexation, and emulsification. Their detailed process is summarized in the present review with a focus on the latest findings. The fat-mimic mechanisms of fat replacers have received little attention compared to the fabricating methods; attempts are also made to explain the underlying principles of fat replacers from the physicochemical prospect. Finally, a future direction on the development of desirable fat replacers in a more sustainable way was also pointed out.

A dynamic in vitro oral mastication system to study the oral processing behavior of soft foods

A bolus-oriented artificial oral mastication system was developed to simulate the dynamics of food mastication in the human mouth. The system consists of a chewing unit, a bolus forming unit, and provisions for the dynamic incorporation of saliva during mastication. The system performance was validated with in vivo trials (n = 25) considering time-dependent changes in particle size, textural attributes and rheological behavior of the bolus. Idli, a fermented and steamed black gram-rice-based Indian food was considered the model soft food for all trials measured in triplicates. The mastication dynamics were evaluated by analyzing bolus properties during every 3 s of mastication. Large strain shear rheology tests revealed that the viscosity of the sample decreased over time. Results of in vivo trials follow close trends in particle size and rheological behavior and have no significant change in correlation with in vitro mastication results. Similar observations were made in the half softening time of idli during mastication as determined using the relative change in hardness (hardness ratio (H_t/H₀)) values fitted to the Weibull model. Also, a model to simulate the time-dependent changes in bolus adhesiveness was developed.

Future perspectives on aptamer for application in food authentication

Food fraudulence and food contamination are major concerns, particularly among consumers with specific dietary, cultural, lifestyle, and religious requirements. Current food authentication methods have several drawbacks and limitations, necessitating the development of a simpler, more sensitive, and rapid detection approach for food screening analysis, such as an aptamer-based biosensor system. Although the use of aptamer is growing in various fields, aptamer applications for food authentication are still lacking. In this review, we discuss the limitations of existing food authentication technologies and describe the applications of aptamer in food analyses. We also project several potential targets or marker molecules to be targeted in the SELEX process. Finally, this review highlights the drawbacks of current aptamer technologies and outlines the potential route of aptamer selection and applications for successful food authentication. This review provides an overview of the use of aptamer in food research and its potential application as a molecular reporter for rapid detection in food authentication process. Developing databases to store all biochemical profiles of food and applying machine learning algorithms against the biochemical profiles are urged to accelerate the identification of more reliable biomarker molecules as aptamer targets for food authentication.

Oil Bodies Cream from Olive Paste: Extraction of a Functional Ingredient for Developing a Stable Food Emulsion

Oil bodies (OBs) dispersed in an aqueous medium form a natural emulsion with high physical and microbiological stability. This work was focused on the development of a new protocol for extracting OBs from olive paste, through the extraction of an olive oil body cream (OOBC) with a yield of about 43% (wt/wt) in approximately 2 h. The proximate analysis revealed the presence of moisture, lipids and proteins as well as the contents of polyphenols and flavonoids, and the antioxidant powers were determined. The rheological and tribological performances of the OOBC were evaluated. Moreover, we measured a size distribution in the range of 0.7–1.7 m, by using a standard optical microscope. The results have demonstrated clearly that the OOBC extracted from the olive paste can be used as a functional and vegan ingredient in food emulsions.

Food Texture Design by 3D Printing: A Review

An important factor in consumers’ acceptability, beyond visual appearance and taste, is food texture. The elderly and people with dysphagia are more likely to present malnourishment due to visually and texturally unappealing food. Three-dimensional Printing is an additive manufacturing technology that can aid the food industry in developing novel and more complex food products and has the potential to produce tailored foods for specific needs. As a technology that builds food products layer by layer, 3D Printing can present a new methodology to design realistic food textures by the precise placement of texturing elements in the food, printing of multi-material products, and design of complex internal structures. This paper intends to review the existing work on 3D food printing and discuss the recent developments concerning food texture design. Advantages and limitations of 3D Printing in the food industry, the material-based printability and model-based texture, and the future trends in 3D Printing, including numerical simulations, incorporation of cooking technology to the printing, and 4D modifications are discussed. Key challenges for the mainstream adoption of 3D Printing are also elaborated on.

Determining the glycaemic responses of foods: conventional and emerging approaches

A low-glycaemic diet is crucial for those with diabetes and cardiovascular diseases. Information on the glycaemic index (GI) of different ingredients can help in designing novel food products for such target groups. This is because of the intricate dependency of material source, composition, food structure and processing conditions, among other factors, on the glycaemic responses. Different approaches have been used to predict the GI of foods, and certain discrepancies exist because of factors such as inter-individual variation among human subjects. Besides other aspects, it is important to understand the mechanism of food digestion because an approach to predict GI must essentially mimic the complex processes in the human gastrointestinal tract. The focus of this work is to review the advances in various approaches for predicting the glycaemic responses to foods. This has been carried out by detailing conventional approaches, their merits and limitations, and the need to focus on emerging approaches. Given that no single approach can be generalised to all applications, the review emphasises the scope of deriving insights for improvements in methodologies. Reviewing the conventional and emerging approaches for the determination of GI in foods, this detailed work is intended to serve as a state-of-the-art resource for nutritionists who work on developing low-GI foods.

Gastric emptying pattern and disintegration kinetics of cooked rice in a 3D printed in vitro dynamic digestion model ARK®

Understanding the gastric digestion process is essential for evaluating the bioaccessibility of nutrients from food matrices. The objective of this study was to investigate the kinetics of disintegration and gastric emptying patterns in a 3D printed stomach (ARK®) with white rice as the study sample. Modified power exponential model was used to fit the gastric retention data and the average t 1/2 and t lag values of the solid fractions were found to be 109.22 ± 4.20 and 84.16 ± 5.72 min, respectively. During the disintegration process, the weight percentage of medium size particles (∼0.35 mm) was found to be higher at 30 and 60 min. Moreover, there was a sharp decrease in the percentage of fine particles (<0.125 mm) at 90 and 120 min. The ARK® could effectively mimic the physiochemical process of the human stomach, providing promising insights for future studies on the development of novel and functional food products.

Texture and texture assessment of thickened fluids and texture-modified food for dysphagia management

Thickened fluids and texture-modified foods are commonly used in the medical management of individuals who suffer from swallowing difficulty (known as dysphagia). However, how to reliably assess texture properties of such food systems is still a big challenge both to industry and to academic researchers. This article aims to identify key physical parameters that are important for objective assessment of such properties by reviewing the significance of rheological or textural properties of thickened fluids and texture-modified foods for swallowing. Literature reviews have identified that dominating textural properties in relation to swallowing could be very different for thickened fluids and for texture-modified foods. Important parameters of thickened fluids are generally related with the flow of the bolus in the pharyngeal stage, while important parameters of texture-modified foods are generally related with the bolus preparation in the oral stage as well as the bolus flow in the pharyngeal stage. This review helps to identify key textural parameters of thickened fluids and texture-modified foods in relation to eating and swallowing and to develop objective measuring techniques for quality control of thickened fluids and texture-modified foods for dysphagia management.

Effect of varietal differences on the oral processing behavior and bolus properties of cooked rice

This research explored the impact of in-vivo oral processing on the bolus properties of three rice varieties [white ponni (WP), mappillai samba (MS), and basmati (B)] that were selected based on variations in the amylose content. The amylose and dry matter content of the WP, MS, and B were 4.67, 7.48, and 13.8(%) and 69.57, 60.09, and 70.47(%), respectively. Mastication features (bite-size, chewing time, and chew cycles), bolus properties (particle size distribution, bolus moisture content, rheology, and starch hydrolysis), time-dependent bolus features (rate of incorporation of saliva and saliva content) and, temporal dominance of sensation (TDS) of cooked rice were studied. Results confirmed the significance of oral processing on various bolus characteristics. Moreover, a pronounced correlation between the morphology of rice varieties and mastication features was observed. The structure and textural characteristics of the different rice varieties (MS, WP, B) showed considerable effects on the consumption time (25.7 s, 22.2 s, 17.8 s) and chewing cycles (34, 31, 23). Rate of saliva incorporation was relatively lesser for MS as compared with WP and B. Solid loss followed the trends WP > MS > B. The total starch content of cooked rice boluseswas WP (82.69 ± 0.01%), MS (79.49 ± 0.01%), and B (71.74 ± 0.01%). Further, texture – TDS and flavor – TDS of all varieties were found to be strongly dependent on textural attributes, composition, and oro-sensory perception. This study provides a significant understanding of the oral processing behavior of rice and its bolus, considering the effect of variations in amylose content, texture, and morphology.