Could the use of saliva substitutes improve food oral processing in individuals with xerostomia? A systematic review

On the rheological and sensory properties of a novel natural salivary substitute

The prevalence of xerostomia, the sensation of dry mouth, is estimated at 20 % in the general population and up to 50 % in older adults. Saliva plays different roles during bolus formation: lubrication, mixing, coating, hydration, dissolution, and comminution of food particles. This study proposes and tests artificial saliva formulations mimicking human saliva rheological and sensory perceptions. Shear and extensional rheology were assessed to select the type of formulation closest to saliva rheological characteristics. After evaluating three alternative sources, an extract simulating saliva rheology was produced from flax seeds. Friction coefficient and rheological properties, such as flow curves, relaxation times, and Trouton ratios, were compared favorably with human saliva. The sensory evaluation demonstrated that flaxseed extracts induce perceived mouth hydration, slipperiness, and adhesion exceeding that of human saliva. The flaxseed extract proposed in this can i) be used to study in vitro food oral processing and ii) pave the way to novel natural salivary substitutes to alleviate the symptoms of xerostomia.

Non-pharmacological strategies to alleviate dysgeusia in patients undergoing chemotherapy: A systematic review

PURPOSE

Dysgeusia is a common side effect in oncology patients, significantly impacting their quality of life. This systematic review aims to evaluate the effectiveness of non-pharmacological strategies in treating dysgeusia in patients undergoing chemotherapy or radiotherapy.

METHODS

Adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a comprehensive literature search across five databases: PubMed, Embase, Cochrane Library, CINAHL, and the British Nursing Database. We used the Joanna Briggs Institute Critical Appraisal Tools to assess the quality of the included studies. A harvest plot was used to synthesise evidence about the differential effects of population-level interventions.

RESULTS

Nine studies of non-pharmacological strategies to manage dysgeusia were included. These studies encompassed a variety of interventions, including oral applications and supplements, instrumental techniques, and educational programs. The review identified promising interventions such as cryotherapy and Miraculine supplementation, which showed potential in mitigating taste alterations. Instrumental techniques like photobiomodulation therapy and complementary and integrative medicine approaches, including acupuncture and herbs, were also found to be beneficial. Educational and self-management strategies emerged as effective interventions for empowering patients to manage dysgeusia. Despite the diversity of interventions and the limitations of the included studies, such as small sample sizes and geographical differences, these findings underscore the potential of non-pharmacological strategies in managing dysgeusia.

CONCLUSION

The results support the integration of these strategies into clinical practice, highlighting the importance of multidisciplinary approaches to improve patient care. Further research should prioritize rigorous studies to enhance evidence and explore long-term effects.

Effect of salivary fluid characteristics on the physical features of in vitro bread bolus: From the absence of saliva to artificially simulated hypersalivation

Saliva facilitates food oral processing, bolus formation, swallowing, and sensory perception, in addition to contributing to oral health and phonation. Ageing, health affections, and polymedication are among many causes altering salivary production, modifying the mastication process, the food impregnation ratio, and in turn altering the characteristics of the bolus, swallowing, and digestion. In this in vitro work, using the AM2 masticator apparatus, which replicates the mechanical actions taking place while chewing solid foods and produces realistic food bolus in various oral conditions, we investigated the effect of salivary fluid characteristics, i.e., composition, quantity (from absence to hypersalivation), temperature, and enzymatic action, on the physical characteristics (i.e., particle size distribution (PSD), bolus mass, salivary fluid content) of in vitro boluses of Traditional French baguette. A ready-to-swallow bolus of baguette displayed on average a d50 value (median particle size by mass) of 4.1 ± 0.4 mm, with saliva fluid constituting ∼ 35 % of the final bolus mass. The absence of saliva in mouth led to a deficient oral processing, forming bread boluses constituted by extremely big particles (ca. 80 % of particles had a size > 7.1 mm) that likely cannot be swallowed safely. On the contrary, an excess of saliva favoured an excessive breaking down of bread, leading to bread boluses constituted by smaller particles than those formed under healthy salivary conditions (d50 decreased from 4.1 mm to 3.1 mm), having a higher salivary fluid content (+10 %). On the other hand, the salivary fluid temperature did not affect PSD, d50, bolus mass, or salivary fluid content of in vitro bread boluses, however, the addition of human salivary α-amylase did, favouring particle size reduction (d50 decreased to 2.6 mm). Therefore, beyond the correlation between bolus hydration by saliva and food properties such as hardness and moisture content, our findings indicate that the quantity of salivary fluid present in the oral cavity and the enzymatic activity of salivary α-amylase during bread mastication significantly influence both the particle size distribution and the fluid content of bread boluses, ultimately determining the physical properties of the bolus and, therefore, potentially impacting the subsequent swallowing process.

Extending the shelf life of mango (Mangifera indica L.) fruits by using edible coating based on xanthan gum and pomegranate peel extract

The effect of various concentration of xanthan gum (0.5%, 1%, and 2%) based edible coating supplemented with pomegranate peel extract (0.5 mL) on functional and physico-chemical properties of mango (Mangifera indica L.) fruits were studied during the storage period of 15 days at 22 °C. The application of xanthan gum (XG) based edible formulations with pomegranate peel extract (PPE) was found to be effective to maintain the quality attributes and characteristics like reducing weight loss, respiration rate, ethylene production, maintained total soluble solids (TSS), acidity, pH, texture property, ascorbic acid, phenols, and antioxidant activity as compared to control samples. In general, all tested formulations are effective; but edible coatings based on 2% of XG were found the most potential to prevent the postharvest characteristics of mango fruits while maintaining the quality attributes.