Discrete choice experiment of smoking cessation behaviour in Japan

Background

In spite of gradual increases in tobacco price and the introduction of laws supporting various anti‐tobacco measures, the proportion of smokers in Japan''s population is still higher than in other developed nations.

Objective

To understand what information and individual characteristics drive smokers to attempt to quit smoking. These determinants will help to realise effective tobacco control policy as a base for understanding of cessation behaviour.

Method

Discrete choice experiments on a total of 616 respondents registered at a consumer monitoring investigative company.

Results

The effect of price is greater on smokers with lower nicotine dependence. For smokers of moderate and low dependency, short term health risks and health risks caused by passive smoking have a strong impact, though the existence of penalties and long term health risks have little influence on smokers'' decisions to quit. For highly dependent smokers, non‐price attributes have little impact. Furthermore, the effects of age, sex and knowledge are also not uniform in accounting for smoking cessation.

Conclusion

Determinants of smoking cessation vary among levels of nicotine dependency. Therefore, how and what information is provided needs to be carefully considered when counselling smokers to help them to quit.     

Analysis of farmers' willingness to participate in pasture grazing programs: Results from a discrete choice experiment with German dairy farmers

Over the last decades, the usage of pasture for grazing of dairy cows has decreased considerably. Pasture grazing programs initiated by dairy companies try to counteract this trend. The present paper investigates farmers' willingness to participate in such grazing programs. A special aim was to quantify the price premiums farmers require for program participation and to identify determinants influencing the premium level. The empirical analysis is based on a discrete choice experiment with 293 German dairy farmers. Models are estimated in terms of willingness to accept. It was found that farmers have no substantial preference for whether the pasture grazing program is financed by the food industry, a governmental scheme, or the dairy company. However, an extension of the annual or daily grazing period results in a decreasing willingness of farmers to participate in a pasture grazing program. In addition, farmers decline the option of a feeding standard prescribing the use of only green fodder when offered an alternative program that merely reduces the amount of concentrated feed or maize silage in the diet. Farmers' with an aversion toward program participation have a significant higher price demand for fulfilling the program requirements. Furthermore, the required price premiums increase with growing milk yields and a greater number of cows kept on the farm. However, if the availability of pasture is high, farmers are more likely to participate. The estimated price premiums and factors influencing farmers' willingness to participate found by this study should be considered by dairies and policymakers to gain insights into the design of possible pasture grazing programs from the perspective of farmers. Thereby, paying price premiums to farmers may increase the attractiveness of pasture grazing, which could finally result in an extended usage of pasture grazing.     

鲜奶微过滤除菌初探

介绍了利用微过滤膜去除鲜奶中细菌的工艺流程,对鲜奶微过滤除菌实验进行了初探,并对除去腐败(酸败)微生物和病原菌的效果作出系统评价.     

Short communication: Variation in the composition and properties of Swedish raw milk for ultra-high-temperature processing

The composition and properties of raw milk are of great importance for the quality and shelf life of the final dairy product, especially in products with a long shelf life [e.g., ultra-high-temperature (UHT)-treated milk]. The objective of this study was to investigate the compositional variation in raw milk samples before processing at the dairy plant. Moreover, we wanted to investigate the effect of the UHT process on this variation (i.e., if the same variation could be observed in the corresponding UHT milk). The quality traits analyzed included detailed milk composition, counts of total and psychrotrophic bacteria, proteolytic activity, and color, as well as predictive measures of stability (i.e., ethanol stability and heat coagulating time). Samples of raw milk and the corresponding produced UHT milk were collected and analyzed on a monthly basis during 1 yr. Principal component analysis was used to identify months showing similarities and differences with respect to total variation. In contrast to previous studies, we observed only small variations between months and no clear effect of season for the raw milk. For the UHT milk, July and the winter months (December, January, and February) tended to separate from the other months. Quality traits showing significant variation were only to some extent identical in raw milk and UHT-processed milk. A better understanding of the natural variation in raw milk quality will provide opportunities to improve the shelf life of UHT-treated milk products.     

Graduate Student Literature Review: Current understanding of the influence of on-farm factors on bovine raw milk and its suitability for cheesemaking

Relationships between dairy farm practices, the composition and properties of raw milk, and the quality of the resulting cheese are complex. In this review, we assess the effect of farm factors on the quality of bovine raw milk intended for cheesemaking. The literature reports several prominent farm-related factors that are closely associated with milk quality characteristics. We describe their effects on the composition and technological properties of raw milk and on the quality of the resulting cheese. Cow breed, composite genotype, and protein polymorphism all have noticeable effects on milk coagulation, cheese yield, and cheese composition. Feed and feeding strategy, dietary supplementation, housing and milking system, and seasonality of milk production also influence the composition and properties of raw milk, and the resulting cheese. The microbiota in raw milk is influenced by on-farm factors and by the production environment, and may influence the technological properties of the milk and the sensory profile of certain cheese types. Advances in research dealing with the technological properties of raw milk have undoubtedly improved understanding of how on-farm factors affect milk quality attributes, and have refuted the concept of one milk for all purposes. The specific conditions for milk production should be considered when the milk is intended for the production of cheese with unique characteristics. The scientific identification of these conditions would improve the current understanding of the complex associations between raw milk quality and farm and management factors. Future research that considers dairy landscapes within broader perspectives and develops multidimensional approaches to control the quality of raw milk intended for long-ripening cheese production is recommended.     

基于选择实验法的消费者食品安全属性偏好行为研究

基于选择实验法(Choice Experiment),运用随机效用参数模型(RPL)和潜在分类模型(LCM)研究消费者对食品安全属性的行为偏好。研究发现,消费者对品牌、产品安全、营养成份、口碑和距保质期时间这四个食品安全属性表现出较强的偏好,价格属性则并不显著(p值为0.582),但与消费者的偏好存在反向关系;不同消费者之间对食品安全属性的偏好存在异质性;出于\     

Microbiological quality of raw milk used for small-scale artisan cheese production in Vermont: Effect of farm characteristics and practices

This study 1) evaluated the overall milk quality and prevalence of 4 target pathogens (Listeria monocytogenes, Staphylococcus aureus, Salmonella spp., and Escherichia coli O157:H7) in raw milk used for small-scale artisan cheesemaking and 2) examined specific farm characteristics and practices and their effect on bacterial and somatic cell counts (SCC). Raw milk samples were collected weekly from 21 artisan cheese operations (6 organic) in the state of Vermont that manufactured raw-milk cheese from cow (12), goat (5), or sheep (4) milk during the summer of 2008. Individual samples were examined for standard plate counts (SPC), coliform counts (CC), and SCC. Samples were also screened for target pathogens both quantitatively and qualitatively by direct plating and PCR. Overall, 86% of samples had SPC <10,000 cfu/mL, with 42% <1,000 cfu/mL. Additionally, 68% of samples tested were within pasteurized milk standards for coliform bacteria under the United States’ Grade A Pasteurized Milk Ordinance at <10 cfu/mL. Log₁₀ SPC and CC did not differ significantly among species. Similarly, method of sample delivery (shipped or picked up), farm type (organic or conventional), and duration of milking (year-round or seasonal) did not have significant effects on farm aggregated mean log₁₀ SPC, CC, or SCC. Strong positive correlations were observed between herd size and mean log₁₀ SPC and between log₁₀ SPC and CC as well as SCC when data from all animal species were combined. Although SCC for cow milk were significantly lower than those for goat and sheep milk, 98, 71, and 92% of cow, sheep, and goat milk samples, respectively, were within the compliance limits of the United States’ Grade A Pasteurized Milk Ordinance for SCC. Fourteen of the 21 farms (67%) were positive for Staph. aureus, detected in 38% of samples at an average level of 20 cfu/mL. Neither L. monocytogenes, E. coli O157:H7, or Salmonella spp. were detected or recovered from any of the 101 samples tested. Our results indicate that the majority of raw milk produced for small-scale artisan cheesemaking was of high microbiological quality with no detectable target pathogens despite the repeat sampling of farms. These data will help to inform risk assessments that evaluate the microbiological safety of artisan and farmstead cheeses, particularly those manufactured from raw milk.     

Labeling strategies to overcome the problem of niche markets for sustainable milk products: The example of pasture-raised milk

Pasture-raised milk is gaining in importance in some European countries and in the United States. The production of pasture-raised milk is linked to higher costs, as the milk is normally collected and processed separately from conventional barn milk. This could hinder the production of sustainable milk products. We discuss alternative labeling strategies that allow the mixing of pasture-raised (sustainable) and conventional milk to reduce costs and break free from the current niche market. The lower price would allow for more pasture-raised milk to be produced and enter the mainstream market. The aim of this study was to analyze consumers' willingness to pay for alternative labeling types using a discrete choice experiment with 1,065 German milk buyers. The 2 alternative labels, besides the classical labeling approach, are based on the mass balance approach (at least 50% pasture-raised milk in a package) and cause-related marketing (support of farmers who keep their cows on pasture). The discrete choice experiment was combined with a cluster analysis to get a deeper understanding of the buying behavior of the diverse consumer segments for milk. We found that all consumer groups prefer the classical label where products are segregated but also understand the benefits of cause-related marketing. The average consumer was willing to pay €0.50 more for pasture-raised milk certified with the classical label and €0.38 more for pasture-raised milk labeled with a cause-related marketing claim. However, differences between the clusters are strong: The smallest cluster of ethically involved consumers (15%) is willing to pay the highest premiums, especially for the classical label. Cause-related marketing is an interesting alternative for involved buyers under price pressure (41%), whereas the mass balance approach is little understood and thus less valued by consumers. From our results we concluded that cause-related marketing (in our case, the support of pasturing of dairy cows) can be useful for dairies for which it is not efficient to collect and process products separately. This approach is furthermore suitable for reaching consumers who are mainly interested in altruistic issues but at the same time are more price sensitive, as this labeling strategy does not need separate collection and processing and can thereby be marketed at a lower price.     

Development of a novel loop-mediated isothermal amplification assay for the detection of lipolytic Pseudomonas fluorescens in raw cow milk from north China

Lipases secreted by psychrotrophic bacteria are known to be heat resistant and can remain active even after the thermal processing of milk products. Such enzymes are able to destabilize the quality of milk products by causing a rancid flavor. Rapid detection of a small amount of heat-resistant lipase-producing psychrotrophic bacteria is crucial for reducing their adverse effects on milk quality. In this study, we established and optimized a novel loop-mediated isothermal amplification (LAMP) assay for the detection of Pseudomonas fluorescens in raw cow milk, as the most frequently reported heat-resistant lipase-producing bacterial species. Pseudomonas fluorescens-specific DNA primers for LAMP were designed based on the lipase gene sequence. Reaction conditions of the LAMP assay were tested and optimized. The detection limit of the optimized LAMP assay was found to be lower than that of a conventional PCR-based method. In pure culture, the detection limit of the LAMP assay was found to be 4.8 × 10¹ cfu/reaction of the template DNA, whereas the detection limit of the PCR method was 4.8 × 10² cfu/reaction. Evaluation of the performance of the method in P. fluorescens-contaminated pasteurized cow milk revealed a detection limit of 7.4 × 10¹ cfu/reaction, which was 10² lower than that of the PCR-based method. If further developed, the LAMP assay could offer a favorable on-farm alternative to existing technologies for the detection of psychotrophic bacterial contamination of milk, enabling improved quality control of milk and milk products.     

原料乳掺假现场检测箱的设计与检测项目组合

提出了原料乳掺假现场检测箱的设计思路,利用若干化学反应的基本原理和现象,可检测出原料乳中21种掺假物质。通过系统的评价各种检测方法的检测限,给出了优化后试剂组合。该检测箱适用于现场检测,便于携带。     

Understanding influencing attributes of adolescent snack choices: Evidence from a discrete choice experiment

The quality of diet is crucial to the health and well-being of America’s adolescents. While a critical step in the goal toward healthier eating is facilitated by school nutrition guidelines that address the food environment, additional information on snack preferences can contribute to this goal. The purpose of this study was to determine which snack nutrient and snack characteristic attributes affect adolescent snack choices and quantify their relative importance. The method used in this study was a discrete choice experiment (DCE) designed with a unique approach of block fractional factorial designs. The study participants were middle school students, aged 11 to 13 years old (n=166) from an underrepresented, minority-serving middle school in Orange County, California. A mixed logit model was used to analyze the data from DCEs that examined five snack nutrients and five snack characteristics. The results indicated whole grains had the highest relative importance of snack nutrients followed by salt, protein, calories and sugar. Students were more attentive to negative nutrients when two attributes interacted. Price had the highest relative importance of snack characteristics followed by nutritiousness, social, taste, and convenience. Students were more likely to choose a snack in which their family eats even if the snack was low in nutrient content. Understanding students’ preferences can potentially enhance healthy eating practices on school campuses. This provides implications for stakeholders working to implement and comply with federal school nutrition guidelines.     

Traditional Colonial-type cheese from the south of Brazil: A case to support the new Brazilian laws for artisanal cheese production from raw milk

Artisanal Colonial-type cheese is made from raw milk and is the main cheese produced by rural families of the southern region of Brazil. The aim of this study was to investigate, identify problems, and propose solutions for the current situation of small family farms producing and informally selling artisanal Colonial-type cheese located in the western part of Santa Catarina State in Southern Brazil. A semistructured questionnaire was employed in 12 rural properties to analyze the mode of production. Physical-chemical and microbiological analyses of water, raw milk, and cheese were performed, and it was found that 92, 50, and 100% of the samples, respectively, were outside of the current Brazilian regulatory parameters. None of the cheesemakers involved in this study met the requirements, as established by law, for artisanal cheese production from raw milk. This study concluded that technical support and changes in public policy are needed to ensure the preservation of this artisanal cheese, considering the historical importance and cultural traditions of these local communities and the socioeconomic importance of cheesemaking to family farming. Furthermore, more research on the safety of the cheese produced from raw milk is needed as well as the development of specific microbiological standards for artisanal Brazilian cheeses. Public policies aimed at guaranteeing food safety that formalize the commercialization of these cheeses will increase food security in those communities that currently produce artisanal cheese informally.     

Bayesian validation of a serum and milk ELISA for antibodies against Mycobacterium avium subspecies paratuberculosis in Greek dairy goats across lactation

We validated a commercial (Idexx Pourquier, Montpellier, France) serum and milk indirect ELISA that detects antibodies against Mycobacterium avium ssp. paratuberculosis (MAP) in Greek dairy goats. Each goat was sampled 4 times, starting from kidding and covering early, mid, and late lactation. A total of 1,268 paired milk (or colostrum) and serum samples were collected during the 7-mo lactation period. Bayesian latent class models, which allow for the continuous interpretation of test results, were used to derive the distribution of the serum and milk ELISA response for healthy and MAP-infected individuals at each lactation stage. Both serum and milk ELISA, in all lactation stages, had average and similar overall discriminatory ability as measured by the area under the curve (AUC). For each test, the smallest overlap between the distribution of the healthy and MAP-infected does was in late lactation. At this stage, the AUC was 0.89 (95% credible interval: 0.70; 0.98) and 0.92 (0.74; 0.99) for the milk and serum ELISA, respectively. Both tests had comparable sensitivities and specificities at the recommended cutoffs across lactation. Lowering the cutoffs led to an increase in sensitivity without serious loss in specificity. In conclusion, the milk ELISA was as accurate as the serum ELISA. Therefore, it could serve as the diagnostic tool of choice, especially during the implementation of MAP control programs that require frequent testing, because milk sampling is a noninvasive, rapid, and easy process.     

Evaluation of indigenous lactic acid bacteria of raw mare milk from pastoral areas in Xinjiang,China, for potential use in probiotic fermented dairy products

In the present study 114 lactic acid bacteria strains, isolated from raw mare milks from pastoral areas for ethnic minorities in northwest China, were screened for probiotic traits, and their characteristics were compared with those of Lactobacillus rhamnosus GG, a commercial strain. Among the 114 strains identified, the most common species was Pediococcus pentosaceus (n = 52), followed by Leuconostoc lactis (n = 35), Lactobacillus helveticus (n = 7), Lactobacillus plantarum (n = 6), Lactobacillus kefiri (n = 5), Lactobacillus curvatus (n = 4), Lactobacillus paracasei (n = 3), and Lactococcus garvieae (n = 3). Based on acid and bile salt tolerance, 15 strains were further selected. All selected strains were subjected to a series of in vitro tests to assess their technological properties, including cell surface hydrophobicity (13.6–56.2%), autoaggregation ability (9.26–38.30%), coaggregation ability, and heat and lysozyme survival rates (84.74–94.01% and 80.52–99.37%, respectively). In vitro antagonism showed that Lb. plantarum (M5–19, M8–60, M8–59) exhibited the most strong inhibitory activity against 7 tested pathogens. Moreover, antibiotic resistance and hemolytic activity were investigated for safety assessment. No strain exhibited hemolytic activity, and most of the strains were sensitive to a series of 14 antibiotics of clinical importance. Ultimately, the principal component analysis of all data obtained above showed that 2 Lb. plantarum strains (M8–59, M8–60) and Lb. paracasei M1–36 exhibited the best potential for their inclusion as adjunct functional cultures in local fermented dairy products.     

Determination of the transfer of lead and chromium from feed to raw milk in Holstein cows

ABSTRACT

In this study, we aimed to determinate the transfer of lead (Pb) and chromium (Cr) from feed to raw milk in Holstein cows. Solutions of lead acetate and chromium (III) nicotinate were added together at different levels to individual portions of feed on a daily basis. Lead administration for the low-, middle- and high-dosage groups was controlled as 0.9, 1.8 and 3.6 g/day for 30, 30 and 25 days, while chromium was feed at 0.47, 1.5 and 4.7 g/d for 40, 40, and 40 days, respectively. A sensitive graphite furnace atomic absorption spectrometry (GFAAS) method was developed and optimised with a respective limit of detection of lead and chromium found to be 1 and 5 μg kg^?1 raw milk. The optical wavelengths for detection of lead and chromium were 283.31 nm and 357.87 nm respectively. The results showed that the highest concentrations of lead in raw milk for the low-, middle- and high-dosage groups were 0.083 ± 0.021, 0.215 ± 0.064 and 0.232 ± 0.035 mg kg^?1, which displayed a positive correlation with dosage levels. In addition, a high dosage level accompanied a greater rate of loss of lead contents after dosing withdrawal. However, chromium concentrations maintained a relatively stable range around 0.1 mg kg^?1 raw milk for all dosing groups and showed little transfer from feed to raw milk through the whole experiment.     

Consumer willingness to pay for quality attributes of fresh seafood: A labeled latent class model

We applied a labeled choice experiment (LCE) to investigate consumer demand and choice behavior for fresh seafood in a retail market. The LCE was conducted for a large number of seafood alternatives (i.e., seafood species) labeled by the respective seafood name (e.g., cod, salmon, mussels). Consumer heterogeneity in preference was expressed by estimating a labeled latent class model with alternative-specific effects, which varies choice probability and model parameters over seafood alternatives and across classes. The willingness to pay (WTP) for extrinsic attributes (e.g., product form, production method, and country of origin), and the rank ordered-intrinsic value were estimated for each seafood alternative within classes and the entire market. The WTP estimate in our study is expected to be more accurate than those derived from studies based on single product alternatives because the LCE allows respondents to evaluate choice alternatives through both attribute judgment and alternative comparison. Exploring a variety of product alternatives is also meaningful to firms with multiple products (e.g., fresh seafood retailers) or firms with many direct competitors.