Intensity Of Chewing Research Articles

Immediate and residual effects of functional chewing gum on sustained attention and mood

ABSTRACT Objectives: Chewing gum has been shown to improve aspects of cognition and mood with sustained attention being particularly receptive to the effects of chewing. Chewing gum may also be a useful vehicle for administering functional ingredients. The herbal extract Rhodiola rosea and certain B-vitamins have previously been shown to improve aspects of cognition and subjective state, but their combined effects have not been studied to date. Methods: The current randomised, placebo-controlled, double-blind, balanced crossover study compared the effects of a functional gum containing Rhodiola rosea and B-vitamins to flavour-matched regular chewing gum and a flavour-matched placebo. Thirty-six healthy young participants completed measures of attention and mood at baseline, during chewing, and 1-h after chewing. Results: Chewing both functional and regular gum was shown to reduce errors on a digit vigilance task compared to placebo irrespective of whether measured during or after chewing. There were no benefits to adding functional ingredients to the gum. Discussion: Future chewing research should consider different formats of placebo. Sex differences in response to chewing and the impact of rate and intensity of chewing should also be explored. Trial registration: ClinicalTrials.gov identifier: NCT05544500.

Potential impact of natural conditions on the rostral oral health: a study of horses in Iceland.

In the context of a study of Equine Odontoclastic Tooth Resorption and Hypercementosis (EOTRH), elderly Icelandic horses were examined in their originating country. The subject of this survey was the impact of dental treatment and keeping and feeding management on the health of the rostral oral cavity. A total of 170 horses (aged ≥ 15) located in different areas of Northwest, West, and South Iceland. The horse owners completed a questionnaire about keeping, feeding, and preventative dental care. The horses were clinically examined with particular attention to gingival and dental disorders of the rostral mouth, such as gingivitis, fistula, gingiva retraction, enlargement of the roots and dental calculus as well as integrity of incisors, bite angle, and tooth mobility. Most of the horses were kept on pasture all year with little supplementary feeding. The frequency of dental treatment in Iceland was low. Only a few horses were affected by tooth loss, gingivitis, gingival recession, and incisor calculus. Calculus occurred more frequently and more severely in canines than in incisors. The findings did not depend on the location of the horse. Assuming that the remarkable health of the rostral oral cavity in elderly Icelandic horses was not caused by preventive dental care, it is likely that it was due to living conditions in Iceland. Continuity, intensity of chewing, and nativeness of forage might promote the health of incisors and tissue surrounding the tooth even in elderly horses.

Effect of physically effective fibre on chewing behaviour, ruminal fermentation, digesta passage and protein metabolism of dairy cows

Dietary fibre concentration and particle size influence chewing behaviour, ruminal fermentation and digesta passage in dairy cows and through this, may impact nitrogen (N) use and excretion by the animals. The aim was thus to evaluate the effects of physically effective neutral detergent fibre (peNDF) concentration on chewing behaviour, ruminal fermentation, passage rate and protein metabolism in four lactating, rumen-cannulated Holstein cows in a 4 × 4 latin square design. Four total mixed rations with identical ingredients, chemical composition and a negative ruminal N balance (–2.1 g/kg dry matter) were tested. They varied in peNDF concentration, adjusted by feed mixing time: low (L), medium-low (ML), medium-high (MH) and high (H) peNDF. Nutrient intakes, number of total chews, organic matter digestibility and yield and efficiency of ruminal microbial protein synthesis responded quadratically to increasing peNDF concentration, with greater values for MH and ML diets. While rumination and total chewing intensity (min/kg dry matter) increased with increasing peNDF concentration, milk yield and composition, digesta passage rates and concentrations of ammonium-N and volatile fatty acids in rumen fluid were similar across diets. Energy-corrected milk yield and partitioning of N between milk and urine responded quadratically to increased peNDF concentration. Energy-corrected milk yield and the percentage of ingested N secreted via milk were lower, but the percentage of N intake excreted via urine was greater for MH and ML diets. Hence, feeding dairy cows a low-protein diet with varying peNDF concentrations affects their chewing behaviour, nutrient digestion and protein metabolism.

Individual differences in digesta retention and their relation to chewing in cattle-A pilot investigation.

While information on individual differences in digesta mean retention time (MRT) might be interesting when selecting phenotypes for digestive efficiency, MRT measurements are prohibitively labour-intensive for large-scale application. Therefore, more easily measured proxies of MRT might be helpful. We used the opportunity of an experiment applying saliva stimulant in cattle to investigate the effect of different individual chewing behaviour on fluid and particle MRT with a consistent diet. Four non-lactating cattle (670-850 kg body mass [BM]) were used in a 4 × 4 Latin square design, treated with the saliva stimulant pilocarpine in dosages of 0, 1, 2.5and 5 mg/kg BM per day. The cattle were fed hay with dry matter intake (DMI) assigned according to their metabolic body weight. MRT in the whole gastrointestinal tract (GIT), the reticulorumen (RR) and the distal tract were measured using Co-EDTA, Cr-mordanted fibre and La-mordanted fibre as markers representing fluid, small particles (2 mm) and large particles (1 cm), respectively. The chewing behaviour was measured via noseband pressure sensor and expressed as chewing frequency (chews per time) and chewing intensity (chews per DMI), both for total chewing (ingestion plus rumination) and rumination chewing alone. The animals differed considerably in chewing behaviour and MRT measures. BM did not show a significant effect on chewing behaviour and MRT measures, though it tended to negatively correlated to total chewing intensity. Chewing intensity exerted a significant negative influence on MRT of fluid and particles in the RR, which was not the case for chewing frequency. Chewing frequency showed a significant relationship with MRT of large particles in the GIT. We suggest that chewing behaviour could influence MRT in two ways: (i) by affecting saliva production via the masticatory-salivary reflex and subsequently, the fluid inflow to the RR; (ii) by contributing to particle size reduction. Should the link between chewing behaviour and MRT be corroborated in larger studies, chewing measures, with their large interindividual variation, could emerge as an easy-to-measure proxy for MRT characteristics.

Feed Intake Parameters of Horses Fed Soaked or Steamed Hay and Hygienic Quality of Hay Stored following Treatment.

Simple SummaryDusty hay is particularly harmful to horses with equine asthma, where the dust mainly consists of microbial deposits in addition to abiotic ones. Soaking and steaming hay can improve its hygienic quality by rinsing off dust, but also reducing the viability of microorganisms. In this study, we investigated whether the treated hay remains stable during subsequent storage, and how the horses’ feed intake as well as chewing activity change with treated hay. Microbial counts were determined by culture methods in meadow hay before and after soaking or steaming, and subsequent storage at 10 and 25 °C for 6, 12 and 24 h. Chewing activity was monitored while horses consumed native or treated hay. Steaming effectively reduced yeasts and typical mold. Steamed hay was almost stable during storage, but storing soaked hay increased yeasts, and typical bacteria and mold. The intake of soaked hay was characterized by a particularly low consumption rate and high chewing intensity, but these per se positive effects seemed to be biased by a lower acceptance. However, steaming can be used to reduce counts of viable microorganisms. The feeding of soaked hay is recommended directly after treatment, to avoid hygienic problems.Horses suffering from equine asthma must consume low-dust forage, with soaking and steaming being suitable methods of hay treatment. The impacts of this treated hay’s subsequent storage and effects on the horses’ chewing activity are largely unknown. Meadow hay was soaked (10–15 °C, 15 min) or steamed (100 °C, 60 min). Microbial counts (colony forming units (CFU)) were determined by culture before and after soaking or steaming, and subsequent storage at 10 and 25 °C for 6, 12 and 24 h (three replicates each). Six horses were fed native, soaked and steamed hay, according to a cross-over design, and chewing parameters were measured. Steaming reduced (p < 0.05) typical mold vs. soaking (0 vs. 50 CFU/g) and yeasts vs. native and steamed hay (0 vs. 102 and 90 CFU/g). Storing soaked hay elevated bacteria, mold, and yeasts (p < 0.05). Within the first 60 min of hay intake, the steamed hay and soaked hay were eaten slower (19.5 and 21.5 g dry matter/min, respectively; p < 0.05) and the steamed hay was chewed more intensely (steamed hay: 3537; native: 2622; and soaked: 2521 chewing cycles/kg dry matter, p < 0.05). Steaming particularly improves the hygienic quality of hay. Soaked hay is not stable when stored and is less accepted by horses.

Formulation and Evaluation of Medicated Chewing gum consisting of Dextromethorphan and Guaifenesin for the treatment of cough

Common cold is the most frequently recurring disease in the world and is a leading cause of doctor visits and missed days from school and work. Cold reliever medicated chewing gum (MCG) will be a definitive patient acceptable solution for this condition. Dextromethorphan hydrobromide and guaifenesin will be easily released from chewing gum into the salivary fluid within few minutes of chewing and can be easily permeated from oral mucosa by the pressure created by the chewing action and absorbed to a larger extent into the systemic circulation. Therefore, ultimately patients will get quick relief from symptoms of common cold with greater compliance compared to other conventional dosage forms. This study mainly focuses on taste masking of dextromethorphan hydrobromide and guaifenesin with Kyron T-114, its formulation development in the MCG form and its quality and performance evaluation with the study of potential factors affecting drug release by 32 full factorial experimental design. Formulation ingredients, such as elastomers, softeners, bulking agents, play an important role in the feel of the final product and its consistency; while sweeteners and flavours play a very essential character in its sensory properties. Inter individual variation in chewing frequency and chewing intensity is the main factor which affects release of active ingredient from MCG; while salivary dilution and involuntary swallowing are main reasons for variability in the absorption site, i.e., either from buccal mucosa or from gastrointestinal tract.

Increasing feed intake in domestic goats (Capra hircus): Measured effects on chewing intensity are probably driven by escape of few, large particles from the forestomach

On the one hand, oral processing – mastication – is considered a relatively inflexible component of mammalian feed acquisition that constrains instantaneous intake rates. On the other hand, experimental data shows that the level of feed intake affects faecal particle size and hence net chewing efficiency in ruminants, with larger particles occurring in the faeces at higher intakes. Here, we report the effect of an increased feed intake during maintenance (L1), late (200% of L1) and peak lactation (300% of L1) of a consistent diet (hay:concentrates 50:50) in eight domestic goats on various measures of digestive physiology including faecal mean particle size (MPS). Increasing intake led to an increased gut fill, a reduction in digesta retention times, and an increase in faecal MPS (from 0.57 to 0.72 mm). However, this was an effect of the large particle fraction (>2 mm) being disproportionately excreted at higher intakes; if MPS was assessed on the basis of particles below the typical escape threshold (≤1 mm), there was no difference between intake levels. These findings suggest that the effect of intake on the calculated net chewing efficiency in ruminants may rather be an effect of increased large particle escape from the forestomach than a reduced chewing intensity per bolus during ingestion or rumination.

Chewing patterns in horses during the intake of variable quantities of two pelleted compound feeds differing in their physical characteristics only

Pelleted feeds (PF) are popular in horse nutrition because of high palatability and improved feeding hygiene, but ingestion is faster for PF than for cereals or muesli feed. The aim of the study was to evaluate whether variable amounts of two PFs produced with different physical properties from the same batch of feed can affect feed intake patterns in horses. Chewing patterns were measured in six warmblood mares (519 ± 36.3 kg) on two PFs (small-sized PF1: ø 5 mm, length 21.9 ± 4.97 mm, large-sized PF2: edge length 15.6 ± 0.14 × 15.6 ± 0.08 mm, length 54.4 ± 9.59 mm) in three different amounts (1.0, 1.5, 2.0 kg) once per day additional to hay. PF 2 was ingested faster than PF1 for the meal size 1.0 kg, but PF 1 was ingested more rapidly with a reduced chewing intensity if the offered meal size increased. The ingestion of PF 2 tendentially elevated the chewing intensity at higher meal sizes. An additional, but inverted meal size effect compared to 1.0 kg, was observed for 1.5 kg, where PF 1 was ingested at a higher speed combined with a lower chewing intensity compared to PF 2. Independent from the offered amount, PF 2 induced a markedly increased saliva production combined with a higher daily water intake. Larger-sized pellets seem to intensify the chewing process and decelerate the ingestion time if the meal size becomes larger.

Feed intake patterns of sport ponies and warmblood horses following iso-energetic intake of pelleted fibre-rich mixed feed, muesli feed and semicrushed oat grains.

The aim of the study was to compare diverse feed intake patterns in sport ponies and warmblood-type horses after feeding iso-energetic amounts of three different concentrates: a pelleted fibre-rich mixed feed (PF), a muesli feed (MF) and semicrushed oat grains (OG). Four sport ponies and six warmblood-type horses received the concentrates and meadow hay according to maintenance (0.52MJ metabolizable energy (ME)kg body weight (BW)0.75 /day). Both breeds were allocated at random to three groups and received once daily for 8days either OG (1g starch/kg BW/meal) or iso-energetic quantities of PF and MF according to a crossover design. On the 8th day, feed intake patterns (chewing frequency (CF) in number of chewings (NC), NC/s), feed intake time (FITDM , min/kg dry matter (DM); FIT(neutral detergent fibre)NDF , min/kg NDF) and chewing intensity (CI, NC/kg DM) were measured using modified halters. In warmbloods, PF tended to be ingested faster than MF and OG (10.3±1.9, 13.0±1.3, 14.4±2.0min/kg DM, respectively; p=0.05). In ponies, a similar trend was observed (13.5±2.5, 13.6±2.0 and 15.4±1.1min/kg DM, respectively; p>0.05). Ponies needed more time to ingest PF than warmbloods (p<0.05). The CF of ponies was affected by the type of concentrate (PF and MF 1.43±0.11 vs. OG 1.28±0.093 NC/s; p<0.05). The results indicate that concentrate intake of breeds follows a similar pattern and that breed differences were limited to PF only. In both breeds, PF induced chewing patterns different from those observed for OG and/or MF. However, an interpretation of these differences needs to take into consideration the diverse chemical compositions of the concentrates. Upcoming studies should address the throwback regarding PF and also examine the metabolic consequences of concentrate intake in ponies.

Prevalence of abnormal spermatozoa in tobacco chewing sub-fertile males.

AIM:The aim of the following study is to find out the prevalence of abnormal spermatozoa and associated functional parameters in clinical semen samples of sub-fertile males with the tobacco chewing habit.SETTINGS AND DESIGN:Retrospective study was conducted at infertility unit of a tertiary health care center, in a period of 3 years.MATERIALS AND METHOD:Semen of 642 males were analyzed; of them 194 men (30.2%) were tobacco chewers and they were grouped according to their intensity of chewing (<10 and ≥ 10 packets/day). Counts, motility, vitality, and morphology of sperms were analyzed.RESULTS:In tobacco chewers, 66% of subjects were oligozoospermic, 85% asthenozoospermic and 28% teratozoospermic. Sperm counts (odds ratio [OR] =2.2; 95% confidence interval [CI]: 1.5-3.09), motility (OR = 3.2; 95% CI: 2.05-4.9), and normal morphology (OR = 8.4; 95% CI: 4.9-14.6) were significantly affected (P = 0.001) in tobacco chewers than the non-chewing group. Further, in comparison to the intensity of tobacco chewing, patients with the intensive practice of using ≥10 packets/day had a significant effect on sperm morphology (P = 0.003, OR = 2.7; 95% CI = 1.41-5.08) only. Structural defects in head (P = 0.001) and cytoplasmic residues (P = 0.001) were found to be positively correlated with the intensive chewing, but no significant changes were found in anomalies in mid-piece and tail.CONCLUSION:The adverse impact of tobacco chewing on semen parameters was evident even with mild chewers, but with the intensive chewing practice, phenotypes of sperms, mainly defects in the head and cytoplasmic residue were severely affected.

Directly compressible medicated chewing gum formulation for quick relief from common cold

Introduction:Common cold is the most frequently recurring disease in the world and is a leading cause of doctor visits and missed days from school and work. Cold reliever medicated chewing gum (MCG) will be a definitive patient acceptable solution for this condition. Anti-allergic, cetirizine (CTZ) is a BCS class-I (highly soluble and highly permeable) non-sedating antihistaminic drug and this study was based on the hypothesis that CTZ as a BCS class I drug will be easily released from chewing gum into the salivary fluid within few minutes of chewing and can be easily permeated from oral mucosa by the pressure created by the chewing action and absorbed to a larger extent into the systemic circulation. Therefore, ultimately patients will get quick relief from symptoms of common cold with greater compliance compared to other conventional dosage forms.Materials and Methods:This study mainly focuses on taste masking of CTZ by inclusion complexation method, its formulation development in the MCG form and its quality and performance evaluation with the study of potential factors affecting drug release by 32 full factorial experimental design. A “chew out” study is carried out to assess in vivo drug release from MCG, in which residual amount is extracted from the chewed sample.Results:Formulation ingredients, such as elastomers, softeners, bulking agents, play an important role in the feel of the final product and its consistency; while sweeteners and flavors play a very essential character in its sensory properties.Conclusion:Interindividual variation in chewing frequency and chewing intensity is the main factor which affects release of active ingredient from MCG; while salivary dilution and involuntary swallowing are main reasons for variability in the absorption site, i.e., either from buccal mucosa or from gastrointestinal tract.

Comparative ingestive mastication in domestic horses and cattle: a pilot investigation

It is often assumed that horses chew food more intensively during ingestion than cattle, which - as ruminants - complete part of the mastication during rumination. This has been proposed as a reason for more robust mandibles, larger masseter insertion areas and larger masseter muscles in horses as compared to cattle and other grazing ruminants. In this study, we evaluate results of comparative feeding trials with three horses (338-629 kg) and three cows (404-786 kg), on four different roughages. Ingestion time (s/g dry matter) and chewing intensity (chews/g dry matter) differed among animals within a species, indicating an influence of body mass, and differed significantly between different forages. However, although numerical differences clearly suggest that horses have longer ingestion times and higher chewing intensities on high-fibre roughage than do cattle, this could not be proven in this dataset, most likely because of the small number of individuals sampled. Further studies are required to corroborate the suspected ingestive behaviour difference between equids and ruminants.

Assessment of masseter muscle oxygenation during mastication by near-infrared spectroscopy

Orthod Waves-Jpn Ed 2009; 68(1): 1–8Abstract: The purpose of this study was to investigate the effects of gum chewing intensity on masseter muscle oxygenation and blood flow using near-infrared spe...

Investigations on preileal digestion of starch from grain, potato and manioc in horses.

In this study preileal starch digestibility of starchy feeds (oats, corn, barley, potatoes, manioc) was determined in seven jejunofistulated horses. The grains were fed whole (oats, corn), rolled (oats, barley), crushed, ground and expanded (corn); the potatoes were fresh, the manioc rolled. Ground corn was also fed in combination with amylase. The feeds were fed partly isolated or in combination with alfalfa meal or hay (Table 1). At least four horses with a cannula in the terminal jejunum were used for each diet. Two meals per day were offered at 12 h intervals. The starch intake was mostly about 2 g/kg bw/meal, except one period with oats (3.9 g starch/kg bw) and with expanded corn (1.4 g/kg bw). Jejunal chyme was postprandially collected 11 times (from 1st to the 11th h after the morning meal for 15 min). Starch was determined polarimetrically. The preileal digestibility of starch was calculated by the marker method (chronic oxide 0.25% DM) and by estimating the total jejunoileal chyme flow during 12 h postprandially extrapolating the sample volume from the 15 min sampling periods. The results of both methods agreed quite well. Preileal digestibility of oat starch (80-90%) was (independent of doses or preparation or of the combination with hay, Table 4) significantly higher than that of whole or crushed corn (30%) or barley (26%). Grinding of corn significantly increased preileal digestibility to 51%, expanding to 90%. The addition of amylase improved digestion of ground corn by 10% (absolute). The preileal digestibility of potato or manioc was less than 10%. Individual factors in the horse (chewing intensity, amylase activity) had also considerable influence on preileal starch digestibility.

The effects of age, sex, reproductive status and temporal factors on the time-use of free-ranging red kangaroos

The effects of temporal (time of day and season) factors and size, sex, female reproductive state and group size on the diel time-use of free-ranging red kangaroos (Macropus rufus) was examined. Particular emphasis was given to the effects on their foraging behaviour, with foraging divided into cropping, chewing and searching components. The study was conducted in semi-arid western New South Wales from July 1991 to March 1992, a time of deepening drought conditions in New South Wales. Group size had very little influence on the time-use of M. rufus. It was negatively but only weakly correlated with the proportion of foraging time spent chewing (chewing intensity). No significant differences in time-use were found between size classes of adult males (large and medium-sized males), females with or without pouch young, or females with different-sized pouch young (no visible young, small pouch young or large pouch young). Differences occurred between adult males, adult females and subadult kangaroos. These differences were mainly associated with their chewing and searching behaviour and were related to body size; as body size increased the proportion of time spent chewing and the intensity of chewing increased while the proportion of time searching and the proportion of foraging time spent searching (searching intensity) decreased. Neither the proportion of time spent cropping or foraging nor the proportion of foraging time spent cropping (cropping intensity) or the proportion of active time spent foraging (foraging intensity) differed between any size/sex/reproductive class. Temporal effects had a considerable influence on time-use. M. rufus were most active at night and in the few hours after sunrise and sunset. Seasonal changes in time-use were largely a result of changes in daytime behaviour. M. rufus foraged less and rested more during the day in winter than in spring or summer. There was no increase in the intensity or proportion of time spent foraging or cropping at night to compensate for the reduction in diurnal foraging. It is hypothesised that temporal variations in time-use were related to variations in weather and vegetation conditions.

Nicotine gum: Chew rate, subjective effects and plasma nicotine

Two studies were conducted to assess the effects of varying the rate at which single pieces of nicotine gum (4 mg) were chewed. In each study, six cigarette-deprived volunteers were tested during four sessions.In each session they were required to chew the gum for 10 min at varying rates; a variety of self-report and physiologic responses were recorded before and after chewing. All chewed gum was analyzed for amount of nicotine extracted, and blood samples were collected for nicotine analysis. Additionally, in Experiment 2, a measure of masticatory pressure was employed to assess the intensity of chewing and to empirically verify the number of chews. In both studies, we found a weak, but direct, relation between chew rate and the amount of extracted nicotine. Experiment 2 relealed a probable cause of the weaker than expected “dose-effect” function: subjects showed compensatory changes in behavior by chewing slower than instructed in the high rate conditions, and by chewing faster than instructed in the low rate conditions. Thus, despite instructions to vary chew rates across an 8-fold range, actual chew rate varied by only 2.2-fold. Intensity of chewing remained constant across conditions. Taken together, the findings suggest that rate of chewing nicotine gum can make a difference in the amount of nicotine extracted from the gum; however, compensatory changes in chew rate may attenuate attempts to systematically vary nicotine dose in this manner.