Nutrition and chemosensory perception in the elderly

The elderly person's perception of foods and food flavor is affected by age‐associated changes in the chemical senses (taste, smell, and trigeminal sensation). Both classic and modern psychophysical techniques have been applied to achieve some understanding of these changes.

Taste threshold sensitivity declines with age; however, the magnitude of the decline and the degree to which taste qualities are differentially affected remains to be understood. Suprathreshold taste intensity perception is affected by age, but there is a differential effect of taste quality.

Experiments with blended foods have indicated that both olfactory and taste deficits contribute to older people's difficulty with food identification. Experiments assessing threshold sensitivity, suprathreshold intensity, and suprathreshold identification have all demonstrated significant impairment in olfaction in old age. In fact, these effects are far greater than in the taste system.

Patients with Alzheimer's disease show even greater olfactory deficits than normal elderly and the effect is related to the degree of dementia. We have ruled out nasal disease in these patients as the primary causes of olfactory insensitivity, because significant impairment remains when the influence of nasal airflow and nasal cytology has been removed statistically. Both normal elderly and patients with Alzheimer's disease show impairment in odor memory. Sensitivity to, familiarity with, and identifiability of the odors all play a role in odor memory performance.

Flavor preference also changes over the lifespan. Older subjects, for instance, rate high concentration of sugar and salt as pleasanter than young subjects do. Multiple influences contribute to this phenomenon. Elderly persons and those of lower nutritional status have shown preferences for higher concentrations of casein hydrolysate than young persons and those of higher nutritional status, suggesting that dietary preference can be related to chemosensory cues.

There are significant age‐associated changes in chemosensory perception that have the potential to interact with dietary selection and nutrition in the elderly. A better understanding of these phenomena may promote health and well‐being in the elderly.     

Evaluation of volatile compounds and free fatty acids in set types yogurts made of ewes’, goats’ milk and their mixture using two different commercial starter cultures during refrigerated storage

Six different types of yogurt were manufactured from Damascus goat milk, Awassi ewe milk and a mixture of equal portions of the 2 species of milk using 2 types of commercial yogurt cultures (CH-1 and YF-3331). Yogurts were chemically analysed at 1, 7, 14 and 21 days of storage. Results showed that cultures significantly affected acetaldehyde (P < 0.05), acetone (P < 0.05) and diacetyl (P < 0.001) contents. Type of milk significantly influenced acetaldehyde (P < 0.05), diacetyl (P < 0.001), acetoin (P < 0.001) and ethanol (P < 0.05) levels. Significant variations occurred in acetaldehyde (P < 0.001) and acetoin (P < 0.05) contents during the storage. Short-chain free fatty acids were the highest in ewes’ milk yogurt made with culture YF-3331, and increased during storage, while the levels of medium-chain free fatty acids, except for decanoic acid, were unchanged and the amount of long-chain free fatty acids decreased during storage. Cultures used and types of milk had no effect on long-chain free fatty acids in yogurts.     

HACCP在小型乳品厂酸奶生产中的应用

结合小型乳品厂的特点,引入HACCP对酸奶生产进行监控,旨在提高酸奶产品品质,增加产品的安全性,取得了显著效果.     

Hedonic tests in different locations as predictors of apple juice consumption at home in elderly and young subjects

The objective of this study was to evaluate the predictive value of hedonic tests on apple juice carried out in a sensory laboratory, University common room and at home (post-consumption test) on ad libitum home consumption measured over 5 consecutive days. Thirty-five elderly volunteers (59–88 years old) and 33 young subjects (20–30 years old) assessed the degree of liking five apple juices varying in sweetness (0, 2, 4, 7 and 10% w/w sucrose added) on a nine-point hedonic scale. Both age groups judged similarly the juice with the lowest sugar concentrations, whereas the juice with 2% sugar added received lower scores from the elderly compared to the young participants. Those samples with higher sweetness (4, 7 and 10%) received higher scores from the elderly compared to the young people. The sample with no sugar added had higher mean score (all the subjects) in the home test (6.92±1.78) compared to both laboratory (5.51±2.15) and common room (5.92±2.08). No such differences were observed for the juices with the other sugar contents. In the elderly group, 1-day intake of apple juice remained on a similar level, regardless of sweetness liking, while among young adults the intake varied, and was highest for juices that were liked most (with 0 and 2% sucrose added). The results showed that hedonic ratings have a limited value as predictors of fruit juice consumption at home. The correlation between rated degree of liking and intake was low, especially for the elderly (r=0.39), indicating that factors other than pleasantness may affect intake. Among three test conditions, the lowest correlation of juice intake was obtained with laboratory test results (r=0.38), relatively higher—when hedonic tests were conducted in common room setting (r=0.49), or as the post-consumption test at home (r=0.73). Further research is required on sensory procedures relevant for the elderly, which together with some other nonsensory factors, would give a better prediction of consumption.     

Perception of taste and smell in elderly persons

By the turn of the century, there will be considerable shifts in demographics, including a massive increase in our aging population. As we plan for better nutrition in the twenty‐first century, the special sensory and nutritional needs of the elderly must be taken into account. Chemosensory losses, specifically decrements in the senses of taste and smell, can lead to inadequate intake, especially in the elderly sick. These losses result not only from anatomic changes that occur during normal aging but also from certain diseases; pharmacological and surgical interventions, radiation, and environmental pollutants. The design of foods for the elderly that could both compensate for these chemosensory losses and meet nutritional needs presents new challenges and opportunities for the food industry.     

益生菌在酸奶生产过程中对酵母和霉菌污染的控制

以商业生物保鲜菌(干酪乳杆菌)作参照,研究益生菌Laaobacillus casei Zhang在酸奶发酵和贮藏期间对酵母和霉菌污染的控制,及其对酸奶品质的影响.结果表明:酸奶中添加3.00× 106 g-1的L.casei Zhang,能防止酵母和霉菌的污染,具有延长酸奶保质期的效果,且抑菌效果高出商业生物保鲜菌50％.此外,添加L.casei Zhang最多缩短发酵时间1h,减缓酸奶后酸化程度,不影响酸奶贮藏期内酸度、黏度和持水性等.L.casei Zhang具有作为生物保鲜菌的优良特性,可应用于酸奶制品的工业化生产.     

生物增香液对糟烧酒口味的改进及分析

通过由4种原用于白酒增香的微生物培养液（增香液）的扩大培养,将符合要求的种子扩大培养液与酒糟混合,对粉碎后的黄酒糟进行二次发酵,从而得到改良后的糟烧酒,最终利用气相色谱仪对改良前后的样品进行分析。结果表明,二次发酵前后检测出的物质分别有14和16种,二次发酵后的酒样中有2-戊醇和乙醛产生,这些物质存放后经过内部的化学反应,使酒的风味更好,且使酒带有刺激臭和苦涩味的正丁醇含量明显减少。改良前的糟烧酒存在口感不爽,放香不足,后味涩杂等问题,然而经过改良后的糟烧酒口感芳香、绵甜,香味协调,余味悠长。故4种微生物对糟烧酒的风味有一定提升作用。     

Influence of potassium sorbate on the growth of yeasts and moulds in yogurt

Yeasts and moulds are little affected by low pH and may cause spoilage of yogurt during storage. In the present study, potassium sorbate was added as a preservative in concentrations of 0.05%, 0.1% and 0.2%. The unpreserved yogurt showed unfavourable characteristics: yeast and mould counts and acidity increased. The addition of potassium sorbate, however, inhibited yeast and mould levels, with normal characteristic properties extending more than 14 days. Potassium sorbate is thus seen as valuable for preserving yogurt.     

Development and application of predictive models for fungal growth as tools to improve quality control in yogurt production

The effect of storage temperature (0–40 °C) and inoculum size (10¹–10⁵ spores) on the mycelium growth kinetics of 12 fungal species on yogurt were monitored. A cardinal model with inflection (CMI) was used to describe the effect of temperature on the growth rate (μ) and the lag time (λ) of each isolate. Significant differences on the temperature dependence of the mycelium growth between the tested species were observed. Depending on the strain, the estimated minimum, optimum and maximum temperature parameters for μ (T_min, T_opt, T_max) ranged from −7.6 to 9.6, 19.5 to 37.8 and 29.8 to 46.9 °C, respectively. Only λ was found to be affected by the inoculum size and a linear relation between Ln (λ) and Log (inoculum size) was revealed. The inoculum level did not influence the values of T_min, T_opt and T_max for λ. Based on the above observations, the combined effect of inoculum size and temperature on λ was modeled using a modified CMI. The parameter λ_opt (λ at optimum conditions) was expressed as a function of the inoculum size. Validation studies showed a good performance of the developed models. The application scheme of the models for improving fungi control in yogurt productions is discussed.     

Analysis of factors related to illegal tobacco sales to young people in Ontario

OBJECTIVE: To identify and to discuss factors influencing illegal merchant sales of tobacco to underage people in Ontario, Canada. DESIGN: Results were obtained through random retail compliance checks of tobacco merchants. A multivariate analysis specified the relationship between selected independent variables and the willingness of tobacco merchants to sell to minors. The selected independent variables included retail operation type, community population size, the presence of tobacco production, signage, sex and age of volunteers, smoking prevalence rates, and enforcement rates. PARTICIPANTS: A random, stratified sample of 438 tobacco retailers in 186 communities in Ontario. MAIN OUTCOME MEASURE: Willingness of merchants to sell tobacco to minors. RESULTS: Older youths and girls were more likely to be sold tobacco products. Purchase attempts carried out in tobacco-producing regions were also statistically related to illegal sales. CONCLUSIONS: Policy efforts to control youth access to tobacco in Canada may need to invoke legislation requiring merchants to request proper identification from customers who appear to be under the age of 25, and who seek to purchase tobacco products. Further attention could also be directed at tobacco control policies and enforcement strategies that need to consider the unique challenges faced by jurisdictions where the tobacco industry is a powerful presence.     

Hazard perception of Dutch farmers and veterinarians related to dairy young stock rearing

A group of 110 dairy farmers and 26 bovine veterinarians participated in a web-based questionnaire using the adaptive conjoint analysis technique to rank their perception regarding several hazards during 6 subsequent periods of the process of dairy young stock rearing. The method applied only involved selected respondents with a high consistency in their answering (correlation >30%). For the ranking, answers were first transformed into a utility score (US) for each hazard. The final ranking for each of the 6 periods was based on the US per hazard separately for farmers and veterinarians. Besides the ranking, the absolute values and the US itself were also compared between farmers and veterinarians to determine any statistically significant differences between the levels of the score despite the ranking. The overall conclusion is that, for almost every designated period, the ranking of the hazards differed between farmers and veterinarians. Only 1 period was observed (period IV, Pregnancy period until 4 weeks before calving) where veterinarians and farmers had the same top 3 ranking of the hazards, namely “Mastitis,” “Abortion,” and “Poor growth rate of the pregnant heifer.” Major differences between farmers and veterinarians were seen during period II (feeding milk until weaning) for the hazard “Diarrhea in older calf,” which was considered less important by farmers compared to veterinarians, and period number III (weaning until insemination) for “Over-condition,” which, again, was seen as the most important hazard by veterinarians, but only ranked as number 5 by farmers. Besides the ranking, significant differences in absolute US values between veterinarians and farmers were seen in “Infection with Johne's disease” (14.5 vs. 7.8), “Diarrhea in newborn calf” (18.2 vs. 12.2), and “Insufficient feed intake” (16.2 vs. 8.4) in period I (colostrum until transition to milk replacer). Lameness represented the most important significant difference in absolute values in period III (weaning until insemination; 6.3 vs. 14.3), which was again significant in period V (4 wks before calving until calving; 7.4 vs. 12.1). The outcome of this study shows that hazard perception of veterinarians and farmers differs for most rearing periods (in ranking and absolute values). The outcome of this study can be used for 2 purposes: first, to improve communication between farmers and their consulting veterinarian about hazards and hazard perception in young stock rearing; and second, the US scores can be used to select top priority hazards which should at least be integrated into management advisory programs to improve dairy young stock rearing.     

Interactions of protein levels fed to Holstein cows pre- and postpartum on productive and metabolic responses

The objective of this study was to examine the interaction between levels of dietary crude protein (CP) pre- and postpartum on feed intake, performance, and metabolic status of dairy cows with a 14-d close-up experimental period. Forty multiparous Holstein cows were blocked by expected calving date and previous lactation milk yield at ?14 d relative to expected calving and randomly allocated to receive either a 12.5% CP diet with 3.3% rumen undegraded protein (RUP; 12pre) or a 15.2% CP diet with 5% RUP (15pre) based on dry matter (DM). From d 1 to 21 postpartum, cows within each prepartum group were randomly assigned to receive either a 16.1% CP diet with 4.9% RUP (16post) or a 18.6% CP diet with 6.8% RUP (19post) based on DM. The experiment was conducted as a split-plot design, with CP prepartum being the whole-plot factor and CP postpartum as the subplot factor. Diets were similar in net energy for lactation, and CP levels were increased by replacing grain with a combination of corn gluten meal and fish meal. In prepartum, cows fed the 15pre diet tended to consume more DM than cows fed the 12pre diet (9.65 vs. 9.30 kg/d). Except for blood urea nitrogen (BUN) concentration, no other blood metabolite in prepartum was affected by diets. The interaction between pre- and postpartum CP levels showed that elevating dietary CP from 16post to 19post increased DM intake (15.20 vs. 17.67 kg/d) and milk yield (35.16 vs. 40.26 kg/d) in 12pre cows but not in 15pre cows. Milk fat, protein, and lactose contents were not affected by the interaction between pre- and postpartum CP levels. Feeding 19post compared with 16post increased milk protein (1.28 vs. 1.08 kg/d) and lactose (1.86 vs. 1.61 kg/d) yields in 12pre cows, whereas this effect was not observed in 15pre cows. Milk urea nitrogen was elevated when dietary CP increased from 16post to 19post in 15pre cows (12.98 vs. 14.84 mg/dL) but not in 12pre cows. The concentrations of BUN were greater in 19post cows than in 16post cows for both 12pre (16.31 vs. 13.81 mg/dL) and 15pre (18.44 vs. 14.71 mg/dL) cows. The 19post cows had lower serum fatty acids than 16post cows (0.65 vs. 0.96 mmol/L) in 12pre but not in 15pre. However, a reduction in serum aspartate aminotransferase (AST) concentration was observed in 19post cows compared with 16post cows (68.30 vs. 98.24 U/L) when cows were fed 12pre. For cows fed 15pre, those fed 19post had higher serum AST levels than those fed 16post (86.61 vs. 67.74 U/L) during 21 d of lactation. Body weight and body condition score changes were not affected by interactive effects between pre- and postpartum CP levels, but 19post cows tended (?0.30 vs. ?0.45) to have smaller body condition score losses than 16post cows when fed the 12pre diet. Overall, increasing dietary CP postpartum from 16 to 19% DM improved performance and metabolic status of cows fed 12% CP prepartum. The lack of responses to increased dietary CP postpartum in cows fed 15% CP prepartum suggests that dietary CP postpartum could decrease to 16% DM when cows are fed higher dietary CP prepartum.     

Accumulation of coumarin-related compounds in leaves of Matricaria chamomilla related to sample processing

This experiment was carried out to study the influence of sample processing on the quantitative changes of the main coumarin derivative in the leaves of Matricariachamomilla – herniarin and its glucosidic precursors [(Z)- and (E)-2-β-d-glucopyranosyloxy-4-methoxycinnamic acids (GMCAs)]. Fresh and air-dried, as well as heat-dried samples (80, 100 and 120 °C), from four week-old plants were analysed. The content of Z-GMCA was the lowest in fresh samples while the content of herniarin was the highest in fresh samples. E-GMCA was not affected by sample processing. The E/Z-GMCA ratio decreased from fresh to heat-dried samples. The ratio of herniarin/Z-GMCA displayed the same trend. Probable mechanisms of these changes are also considered. The sum of GMCAs and herniarin, calculated as μmol g⁻¹ DW, did not change significantly among all tested variants, to support our assumption that herniarin is not a volatile coumarin derivative.     

Towards a Sustainable Dairy Sector: The underappreciated role of dairy protein in the preservation of lean tissue mass in the elderly

Sarcopenia has been attributed to a diminished postprandial muscle protein synthetic response. Differences in digestion and absorption kinetics of dietary protein and/or its amino acid composition have been suggested to modulate postprandial muscle protein accretion. The amino acid composition of dairy protein, especially whey, has the potential to confer advantages above other nondairy protein sources in prevention of lean tissue mass loss. This may be attributable to its relative high concentration of the essential amino acid leucine.     

Blood parameters of young calves at abattoirs are related to distance transported and farm of origin

Nonreplacement dairy calves, or bobby calves, are fasted and transported to abattoirs from as young as 5 d of age in Australia. The aims of this cross-sectional observational study were (1) to assess the welfare status, as measured by blood parameters, of bobby calves in the commercial supply chain after transport and lairage, and (2) to assess whether distance and duration of transport are risk factors for poor bobby calf welfare, as measured by blood parameters. We hypothesized that bobby calves transported greater distances would be more likely to show evidence of compromised welfare, as measured by blood indicators of hydration, energy status, and muscle fatigue or damage. We also hypothesized that there would be a large amount of variability in indicators of energy status between calves from different farms. We analyzed blood samples collected at slaughter over a spring and an autumn calving period from 4,484 Australian bobby calves aged approximately 5 to 14 d old from 3 different states, after transport, fasting, and lairage. Packed cell volume (PCV), plasma glucose, and serum urea, total protein, β-hydroxybutyrate (BHB), and creatine kinase (CK) were measured. Radio frequency identification ear tag data were used to estimate the distance that the calves were transported and to identify the farm of origin. Data were analyzed using linear mixed models, except for BHB, which was analyzed using a Goodman-Kruskal gamma test due to left censoring of the data. Twelve percent of calves showed evidence of anemia (PCV less than 0.23 L/L), and 11% had urea concentrations consistent with dehydration (urea more than 7.7 mmol/L). Thirty-six percent of calves had CK activity above normal resting values, and 1% of calves had CK >2,000 U/L, indicating muscle fatigue or damage. Distance transported had significant effects on all blood variables except urea and BHB. With increasing distance transported, calves were more likely to show evidence of a negative energy balance (low plasma glucose) or dehydration (high PCV or total protein). The estimated effect of distance overall was small, but for calves transported more than 500 km, plasma glucose concentration declined more per kilometer. The calves' farm of origin accounted for a reasonable amount of the random variation between calves for plasma glucose (20%). Our results suggest that longer transport distances may increase the risk of poor calf welfare (dehydration, negative energy balance) after transport, and on-farm calf management (e.g., nutrition, timing of feeding before transport) may affect transported calves' energy status; improving this area could result in better energy availability during fasting.     

纺织品吸湿速干性能及其测试方法

分析了影响纺织品吸湿速干性能的主要因素及其改善途径,比较了吸水率、滴水扩散时间和芯吸高度等吸湿性能评价指标,以及水分蒸发速率、透湿量等速干性能评价指标的国内外测试方法。     

Refractive and corneal responses of young myopic children to short-term orthokeratology treatment with different compression factors

PurposeTo evaluate changes in refractive and corneal responses in myopic children wearing orthokeratology (ortho-k) lenses with conventional compression factor (CCF, 0.75 D) and increased compression factor (ICF, 1.75 D).MethodsThis was a double-blind self-controlled study. Subjects were randomly fitted with CCF in one eye and ICF in the fellow eye. Weekly monitoring of refraction, visual acuity (VA), external ocular health, and corneal responses were performed over one month of lens wear and after discontinuation of lens wear until stabilization was achieved.ResultsTwenty-five subjects, aged 9.4 ± 1.0 years, completed one-month lens wear, of whom 23 completed the washout period. The first fit success rates for CCF and ICF were 93% and 96%, respectively. Myopia, unaided VA, central corneal thickness, anterior corneal curvatures (K), apical power (AP), and corneal resistance factor (CRF) all changed significantly during the study period (P < 0.003). Between-eye difference was significant only for myopia reduction (P = 0.001). About 4% and 8% of ICF and CCF eyes were under-corrected. The attempted target was achieved in about 80% of CCF and 60% of ICF eyes at week 4. At the end of the washout period (3 weeks), myopia, K, and AP were significantly different compared to baseline (P < 0.001).ConclusionIncreasing the compression factor did not affect the first fit success rate and external ocular health, but did allow faster correction of refractive error within one month of lens wear. Further investigation is warranted to investigate the long-term effects of ICF on myopia control compared to CCF.