Locking up of food between posterior teeth and its influence on chewing efficiency

Current Perspectives on Food Oral Processing

Food oral processing (FOP) is a fast-emerging research area in the food science discipline. Since its first introduction about a decade ago, a large amount of literature has been published in this area, forming new frontiers and leading to new research opportunities. This review aims to summarize FOP research progress from current perspectives. Food texture, food flavor (aroma and taste), bolus swallowing, and eating behavior are covered in this review. The discussion of each topic is organized into three parts: a short background introduction, reflections on current research findings and achievements, and future directions and implications on food design. Physical, physiological, and psychological principles are the main concerns of discussion for each topic. The last part of the review shares views on the research challenges and outlooks of future FOP research. It is hoped that the review not only helps readers comprehend what has been achieved in the past decade but also, more importantly, identify where the knowledge gaps are and in which direction the FOP research will go.

Consensus on the terminologies and methodologies for masticatory assessment

A large number of methodological procedures and experimental conditions are reported to describe the masticatory process. However, similar terms are sometimes employed to describe different methodologies. Standardisation of terms is essential to allow comparisons among different studies. This article was aimed to provide a consensus concerning the terms, definitions and technical methods generally reported when evaluating masticatory function objectively and subjectively. The consensus is based on the results from discussions and consultations among world‐leading researchers in the related research areas. Advantages, limitations and relevance of each method are also discussed. The present consensus provides a revised framework of standardised terms to improve the consistent use of masticatory terminology and facilitate further investigations on masticatory function analysis. In addition, this article also outlines various methods used to evaluate the masticatory process and their advantages and disadvantages in order to help researchers to design their experiments.

The Influence of Initial Breakage on Size Reduction during Habitual Chewing of a Solid Test Food

OBJECTIVES

Food comminution during chewing is due to intra-oral particle selection and subsequent breakage. Under conditions of habitual chewing and a nearly complete selection, the influence of initial breakage on particle size reduction was studied in trials with a first chewing cycle (N = 1) from a sequence of randomized trials with various cycle numbers. Furthermore, relationships were examined between degree of fragmentation from breakage (r-fr), molar maximal bite force (MBF) and chewing efficiency (the number of cycles needed to half the initial particle size, N(1/2-Xo)).

DESIGN

Thirty-one subjects with a natural dentition chewed samples of 2 half-cubes (9.6 × 9.6x4.8 mm) of Optosil®, using sequences with 1-7 cycles, in 2-10 randomized trials; 10 trials with one cycle. Particle size distributions by underweight, characterized by median particle size, X₅₀, were obtained using sieving. N(1/2-Xo) was derived from the log(X₅₀)-log(N) relationship. and r-fr from the cumulative distribution of underweight fractions of damaged particles for N = 1. MBF was determined on both sides of the jaw using a force transducer and averaged.

CONCLUSIONS

A strong, decreasing regression occurred in X₅₀ at N = 1 with r-fr (R² = 0.934, p < 0.001). The decreasing regression of N(1/2-Xo) with r-fr was moderately strong (R² = 0.454; p < 0.001). Thus, initial size reduction is strongly determined by breakage and overall reduction partly, when chewing small amounts of particles. N(1/2-Xo) vs. MBF and r-fr vs. MBF were weakly related (R²≤0.124, p = 0.052-0.127). The lack of a pronounced relationship between r-fr and MBF suggests that either MBF is not relevant but supra-threshold force, or that another factor, occlusion, may influence breakage.