Sustainable Food Consumption: Investigating Organic Meat Purchase Intention by Vietnamese Consumers

: Promoting sustainable food consumption contributes to the achievement of the United Nation’s Sustainable Development Goals. This study investigated the key determinants of consumer intention to purchase organic meat in an emerging market and a unique model was developed by incorporating environmental concern and guilt with the key components of the Theory of Planned Behavior. This model was then validated by obtaining data from a sample of 402 Vietnamese consumers at ﬁve food stores in Ho Chi Minh City, using a paper-based survey. The ﬁndings reveal that consumers who are concerned about the environment are likely to formulate favorable attitudes and downplay monetary barriers associated with organic food purchase. In addition, while attitudes and guilt about buying conventional meat have a positive effect on organic meat purchase intention, perceived monetary barriers signiﬁcantly reduce the intention. These ﬁndings highlight both the rational and emotional aspects of organic food purchase intention and have important implications for key stakeholders and the encouragement of organic meat consumption.


Introduction
Encouraging more sustainable food consumption is critical to future sustainability [1,2]. Fostering the purchase of organic food makes an important contribution to the United Nation's Sustainable Development Goals, especially those relating to sustainable production and consumption. This is because organic agriculture promotes "soil quality, crop rotations, animal and plant diversity, biological processes, and animal welfare, while generally prohibiting irradiation, sewage sludge, genetic engineering, the prophylactic use of antibiotics, and virtually all synthetic pesticides and fertilizers" [3] (p. 1). Given these benefits for environment, human health and animal welfare, consumer demand for organic products has grown substantially. According to the 2019 report by the Research Institute of Organic Agriculture and the International Federation of Organic Agriculture, the global retail sales of organic products have reached over 92 billion euros [4].
Considerable research has sought to identify and examine the various factors influencing organic food purchase intention and consumption using several theories and models such as value theories, rational choice theories (e.g., Knowledge-Attitude-Behavior Model, Theory of Reasoned Action, Theory of Plan Behavior), and normative and ethical models (e.g., Norm Activation Model, Value-Beliefs-Norm Model). Key motivators investigated in prior studies include personal factors (e.g., demographics, personal values, concerns about the environment, health and animal welfare, ethical beliefs, lifestyles, attitudes) and socio-cultural influences (e.g., social norms, media influence, cultural values) [5][6][7][8][9][10][11][12].
food purchase intention and consumption [28,29]. Hence, this theory provides a theoretical background for developing a research model examined in the present study.
In accordance with the TPB, attitudes towards purchasing organic food, subjective norms and perceived monetary barriers (which are used to operationalize PBC) are expected to affect consumer intention to purchase organic food. Moreover, this study extends the TPB by incorporating environmental concern and guilt into the research model. Environmental concern has been identified as an important determinant of environmentally sustainable behaviors [30,31] and organic food purchase [32,33]. The addition of this construct to the TPB can further explain the formation of green attitudes and purchase intentions [34]. In addition, the inclusion of guilt sheds light on how emotional or affective factors affect organic food purchase intention. This is important because many green consumers and organic food shoppers are motivated by emotions and feelings [28,35,36]. The research model is illustrated in Figure 1. The hypothetical relationships between the variables will be explained in the following sections.
or other attributes of the behavior", whereas subjective norms refer to "beliefs about the normative expectations of other people". Perceived behavioral control (PBC) reflects "the perceived ease of difficulty of performing the behavior" [25] (p. 665). The TPB has proved to be effective in predicting various consumer environmentally sustainable behaviors [26,27], including organic food purchase intention and consumption [28,29]. Hence, this theory provides a theoretical background for developing a research model examined in the present study.
In accordance with the TPB, attitudes towards purchasing organic food, subjective norms and perceived monetary barriers (which are used to operationalize PBC) are expected to affect consumer intention to purchase organic food. Moreover, this study extends the TPB by incorporating environmental concern and guilt into the research model. Environmental concern has been identified as an important determinant of environmentally sustainable behaviors [30,31] and organic food purchase [32,33]. The addition of this construct to the TPB can further explain the formation of green attitudes and purchase intentions [34]. In addition, the inclusion of guilt sheds light on how emotional or affective factors affect organic food purchase intention. This is important because many green consumers and organic food shoppers are motivated by emotions and feelings [28,35,36]. The research model is illustrated in Figure 1. The hypothetical relationships between the variables will be explained in the following sections.

Environmental Concern
Consumers' concerns for the environment have been the focus of research in the fields of green purchases and organic food. In its broadest sense, environmental concern denotes "the degree to which people are aware of problems regarding the environment, their support of efforts to solve such problems" [37] (p. 176), and "the affect (i.e., worry) associated with beliefs about environmental problems" [38] (p. 458). Empirical research has operationalized environmental concern as general concerns about environmental quality or specific concerns about environmental problems associated with a behavior or a country [37,[39][40][41]. In general, consumers with greater environmental concern are more Environmental concern Perceived monetary barriers Consumers' concerns for the environment have been the focus of research in the fields of green purchases and organic food. In its broadest sense, environmental concern denotes "the degree to which people are aware of problems regarding the environment, their support of efforts to solve such problems" [37] (p. 176), and "the affect (i.e., worry) associated with beliefs about environmental problems" [38] (p. 458). Empirical research has operationalized environmental concern as general concerns about environmental quality or specific concerns about environmental problems associated with a behavior or a country [37,[39][40][41]. In general, consumers with greater environmental concern are more likely to engage in environmentally friendly behaviors including organic food consumption.
Several prior studies reveal that environmental concern exerts a positive effect on attitudes associate with organic food and the purchase of this green product [42][43][44]. Verhoef [45] asserts that environmental concern plays an essential role in consumer choice of organic meat. Kirk and Slade [46] conclude that consumers form positive attitudes towards organic lamb because such an organic meat is environmentally friendly. Magnusson et al. [47] find that consumers' beliefs about the environmental consequences of organic food purchases positively impact their attitudes towards purchasing organic meat. Hence, we formulated the first hypothesis as follows: Hypothesis 1 (H1). Environmental concern is positively related to attitudes towards organic meat purchase.
Consumers who are concerned about environmental quality are less likely to care about barriers and inconvenience associated with green purchases [48,49]. This is because these consumers tend to assign greater importance to collective outcomes (i.e., better environmental quality) than personal costs such as monetary costs [50]. Scholars such as Perlaviciute and Steg [51] and Van der Werff et al. [52] demonstrate that consumers who endorse environmental values favor environmentally friendly products despite their higher prices. A consumer survey confirms a negative correlation between consumers' environmental concern and their perceptions of the higher monetary costs associated with organic meat purchase [19]. We therefore formulated the second hypothesis as follows: Hypothesis 2 (H2). Environmental concern is negatively related to perceived monetary barriers associated with organic meat purchase.

Subjective Norms
Subjective norms represent pressure to or not to perform an action from others who are important to an individual. Such a social influence is important to the development of consumers' pro-environmental attitudes and actions [53]. In the context of organic food choice, subjective norms have been found to have a positive impact on attitude towards buying organic bread and flour [16]. Lodorfos and Dennis [54] assert that it is important to include subjective norms in models predicting organic food purchase since the pressure from important persons (e.g., friends and family) influence both attitude and purchase behavior. They also found a positive correlation between subjective norms and attitudes among consumers of organic products such as fruits, vegetables and meat. Hence, we proposed the following hypothesis: Hypothesis 3 (H3). Subjective norms are positively related to attitudes towards organic meat purchase.
The TPB posits that subjective norms have a direct impact on consumer behavioral intention. Several empirical studies have confirmed the significance of subjective norms and social pressure in the formation of purchase intentions towards green products including organic food [49,55,56]. Two consumer surveys conducted by Kirk et al. [57] and Wong and Aini [58] revealed that subjective norms significantly enhance consumer intention to purchase organic meat. We therefore proposed the following hypothesis: Hypothesis 4 (H4). Subjective norms are positively related to intention to purchase organic meat.

Attitudes
Attitudes represent favorable or unfavorable evaluation of an object or behavior. Consumers' attitudes are essential in the purchase of organic food since they often need to understand their beliefs and motives to overcome the barriers associated with this behavior [59]. Tarkiainen and Sundqvist [16] report that attitudes towards buying organic food are the strongest predictor of purchase intention. A regression analysis performed by Kirk et al. [57] shows that consumers' attitudes have a positive effect on their intentions to purchase organic meat. Thus, we suggested the following hypothesis:

Perceived Monetary Barriers
Consumers may not intend to purchase green products, owing to several barriers and inconvenience relating to money, time, product availability, risk and unreliable ecolabels [60][61][62]. Perceived monetary barriers refer to consumers' perceptions of the high price of green products and their ability to afford these products [63]. Notably, many consumers perceive monetary barriers associated with organic food purchase as they cannot afford to pay more for organic food which is more expensive than conventional food [63]. While Apostolidis and McLeay [64] assert that that price substantially affects consumer choices toward organic meat, Verhoef [45] found that perceived price level negatively affects consumer choice of such a product. McEachern and Schröder [65] emphasize that despite their awareness of environmental benefits of organic meat, many consumers cannot afford this product and refuse to pay more for it. Thus, we proposed the following hypothesis: Hypothesis 6 (H6). Perceived monetary barriers are negatively related to purchase intention.

Guilt about Consuming Conventional Meat
Baumeister et al. [66] refer to guilt as "an individual's unpleasant emotional state associated with possible objections to one's own actions, inaction, circumstances, or intentions" (p. 245). Guilt may arise when individuals perceive that their actions have violated certain social standard or moral norms [67]. Regular purchase and consumption of conventional meat instead of organic one can make consumers feel guilty since they care about environmental quality and welfare of animals, and such action is against their moral and ethical standards [45,68]. Hence, consumers might want to purchase organic meat to avoid this negative feeling [45]. Hence, we formulated the hypothesis below:

Hypothesis 7 (H7).
Guilt about consuming conventional meat is positively related to purchase intention.
In sum, various hypotheses have been developed as a result of the critical review of relevant research in the areas of pro-environmental behavior, sustainable food consumption, and organic food purchase. Table 1 summarizes all the hypotheses proposed in the current study.

H1
Environmental concern is positively related to attitudes towards organic meat purchase. H2 Environmental concern is negatively related to perceived monetary barriers associated with organic meat purchase. H3 Subjective norms are positively related to attitudes towards organic meat purchase. H4 Subjective norms are positively related to intention to purchase organic meat. H5 Attitudes towards organic meat purchase are positively related to purchase intention. H6 Perceived monetary barriers are negatively related to purchase intention. H7 Guilt about consuming conventional meat is positively related to purchase intention.
Source: the current study.

Measures of the Constructs
We used previously validated scales to measure the constructs presented in the research framework and backward translation between English and Vietnam to design the questionnaire [69]. Specifically, four items were adapted from Lee [41] and Pham et al. [9] to measure country-specific environmental concern (i.e., concern about Vietnam's environment). For attitude towards purchasing organic meat, another four items were adopted from research studies performed by Dean et al. [70] and Arvola et al. [55]. Subjective norms were measured by three items suggested by Arvola [55] and Yadav [44]. Another three items were adopted from Verhoef [45] and Tanner and Kast [63] to measure perceived monetary barriers. Guilt about consuming conventional meat was measured using four items suggested by Verhoef [45]. Specifically, respondents were presented with a scenario that they had purchased conventional meat instead of organic meat, and then asked to indicate the extent to which they felt guilty about that behavior. Finally, purchase intention was operationalized using four items from Nguyen et al. [27] and Pham et al. [9]. To measure guilt, we used a 7-point scale which is anchored at 1 for 'to a very low extent' and 7 for "to a very high extent'. For other constructs, a 7-point Likert scale, anchoring at 1 for "strongly disagree" to 7 for "strongly agree", was used.
Although the aforementioned scales have proved to be valid and reliable in previous studies, the first author conducted two focus groups with organic food consumers and professors of marketing to detect possible issues of utilizing the items in the emerging context of Vietnam. Each focus group consisted of five participants and lasted around 60 min each. There were no problems relating to the scales identified during the focus groups. Hence, all the items (which are shown in the next section) were included in the final questionnaire.

Data Collection and Sample
Prior to data collection, the research protocol including sampling method and data collection procedure was reviewed and approved by Vietnam Foundation for Science and Technology Development in September 2018 (NAFOSTED 502.02-2018.303). We used paper-based questionnaire to collect data from Vietnamese consumers aged over 18 years, who were interested in organic meat. We first conducted a pilot test to identify potential problems with administration and completion of the questionnaire. Specifically, we invited a total of 24 consumers, who voluntarily agreed to participate in the pilot test, to answer the questions, comment on the wording and meanings of the items of measure and the time of completing the questionnaire.
In the main study, we recruited ten experienced research assistants to interview shoppers at five food stores selling organic meat in Ho Chi Minh city, which is the largest city located in the South of Vietnam. Consumers in big cities such as Ho Chi Minh city prove to be suitable subjects in previous studies relating to green consumption, since they are generally aware of environmental issues and earn a higher income than the national average [49,71,72]. Given that it was not possible to obtain an appropriate sampling frame consisting of the shoppers, we adopted convenience sampling which had been used for studying organic food purchase and consumer behavior at retail stores [42,73,74]. Zikmund et al. [75] propose that sample size can be determined based on population size and sample proportion. Accordingly, the target sample size for our study was 400, which would generate a 95% confidence level with a margin of error of about ±5% points.
The research assistants approached every fourth consumers who entered the stores and requested them to voluntarily complete the questionnaire. Consumers were informed that they were free to stop providing their answers at any time, and that completion of the questionnaire was taken as "informed consent". We collected a total of 410 surveys during about two months. The data screening procedure included checking for missing data, normality of distribution and outliers. While there were no missing data and univariate outliers, the results of measuring Mahalanobis distance show that 8 surveys included multivariate outliers. Hence, the final valid sample consisted of 402 respondents, which met the target sample size.

Data Analysis Procedure
The data collected from 402 respondents were subjected to a series of analyses using SPSS 25.0 and AMOS 25.0 (IBM, Armonk, NY, USA). We initially described the characteristics of the sample size. After that, we performed Harman's single factor and latent common methods factor to examine potential common method variance. This was followed by descriptive statistics and reliability analysis. We then conducted a confirmatory  Table 2 illustrates the final sample's demographic characteristics. Our sample included 192 males (47.8%) and 210 females (52.2%), which closely resembles the sex ratio (99 males per 100 females) in the national population reported by the General Statistics Office of Vietnam [76]. Concerning age, approximately 31% were in the 18-29 age category, and 24% aged 50 years and older. This reflected the young population of Vietnam [76]. In addition, around 60% of the respondents were currently married, while 45% had undergraduate degrees. These figures are similar to previous studies of environmentally friendly behavior and green purchases in Vietnam [48,77].

Common Method Variance
Common method variance (bias) may affect sample data which are collected using self-reported methods [78]. We therefore applied different statistical techniques to detect the possible impact of this problem. Initially, according to the Harman's single factor test, we performed an exploratory factor analysis (EFA) on all the items [79]. The EFA results indicated that the single factor explained around 30% of the variance in the variables, indicating that common method bias was unlikely to be a problem in this study [80].
In addition, a CFA was applied to conduct the latent common method factor test which further evaluated the potential problem of common method bias. We allowed all the items to load on their respective variables and on an unmeasured common method factor [68]. We then compared the "standardized regression weights" (β) in the model with the common method factor with those in the model without the factor. Differences between the β values were all less than 0.2, suggesting that common method variance did not have a substantial impact on the sample data [81].  Table 3 shows the results of the descriptive statistics including mean and standard deviation, and reliability coefficient values. The Cronbach's Alpha (α) values (ranging from 0.781 to 0.856) were all greater than the suggested threshold of 0.7 [82]. These findings suggest a good internal consistency of reliability for all the construct measures. The measurement model was established using CFA. The resultant fit indices (Chisquare (χ 2 ) = 274.113; "Chi-square to degree of freedom ratio" (χ 2 /df ) = 1.413; "Goodnessof-fit index" (GFI) = 0.920; "Adjusted goodness-of-fit index" (AGFI) = 0.927; "Tucker and Lewis index" (TLI) = 0.975; "Comparative fit index" (CFI) = 0.979; "Root-mean-square error of approximation" (RMSEA) = 0.032) showed that the measurement model represented a good fit [83].

Descriptive Statistics and Construct Reliability and Validity
The CFA results enable the calculation of composite reliability (CR) and average variance extracted (AVE), which are illustrated in Table 4. Convergent validity was assessed on the basis of factor loadings (FLs), CR and AVE. The FLs (0.688-0.804) were well above the suggested threshold of 0.6 [84]. The values of CR (0.783-0.857) and AVE (0.536-0.599) also met the recommended criteria suggested by Hair et al. [82]. Hence, the constructs' convergent validity was ensured. Additionally, their discriminant validity was also confirmed, given that the square root of AVE of each construct was greater than the bivariate correlations between the constructs [82,83]. Finally, multicollinearity was not a problem because all the correlation values were less than 0.70 [85].

Discussion and Theoretical Implications
This study contributes to the limited knowledge of organic meat consumption in emerging markets [19] via investigation of consumer attitudes and behavior in Vietnam, which is a sizeable country in the Southeast Asian region. The primary objective was to determine the factors that enhance or impede consumer intention to purchase organic meat. This study provided insights via application of the TPB including attitudes, subjective (social) norms, and perceived behavioral control. It also provided insights into organic meat consumption and purchase by considering the relevance of utilitarian and hedonic motives to organic meat consumption. A unique model was initially developed that combined the key components of the TPB, which have been widely used in organic food research [29], with environmental concern and emotion (i.e., guilt). This model was then validated via a survey of Vietnamese consumers.
In terms of theoretical contribution, the analysis revealed support for six of the seven research hypotheses. The important role of environmental concern (i.e., concern about Vietnam's environment) in consumer decisions towards purchasing organic food was confirmed. Specifically, environmental concern was found to enhance attitudes and reduce perceived monetary barriers associated with organic meat purchase. This finding supports the assertion that consumers who care about environmental values and quality tend to develop positive attitudes and downplay the barriers related to pro-environmental behavior [49,50]. It also extends previous research on the positive impact of environmental concern on attitudes towards buying organic food products including organic meat in both developed and developing markets [19,42,43,86,87].
The results also reveal that the TPB is relevant for explaining organic food purchase intention in the context of emerging markets. Attitude had the strongest influence on intention to purchase organic meat, which echoes the findings of a meta-analysis conducted by Scalco et al. [29] that also identified attitude as the most relevant determinant of organic food buying intention. Interestingly, subjective norms in this study were not a significant direct predictor of purchase intention. While this contradicts some prior research about the role of subjective norms in organic food purchase in developed countries [42,54,55,88], a possible explanation is that purchasing organic food has not become a social norm in developing countries [86], including Vietnam. The results in this study however show that subjective norms positively impact attitudes, which supports the finding of Tarkiainen and Sundqvist [16]. This implies that Vietnamese consumers take into account the opinions of important others in their evaluation of organic meat purchase, which can be explained by Vietnam's strong collectivist culture that emphasizes interpersonal relationships [89]. In line with some previous research into organic food [58] and organic meat [45], this study's findings confirmed the negative relationship between perceived monetary barriers and organic meat buying intention. While many consumers in developed countries are willing to pay a high for organic food [90], the finding suggests that Vietnamese consumers still find organic meat expensive and they cannot afford to pay more for it. Indeed, monetary barriers have been widely acknowledged as a serious deterrent to green purchases in developing markets, given the widespread financial constraints in these countries [61]. Thøgersen et al. [91] also point out that consumers with lower income tend to be more price sensitive when purchasing organic food.
The final important finding concerns the significant and positive impact of guilt on green purchase intention. Consumers may feel guilty, unpleasant and regret about the purchase and consumption of conventional meat products, which are detrimental to environmental quality and animal welfare [23]. Such negative feelings encourage them to purchase environmentally friendly and ethically produced products such as organic meat. This finding echoes the research of Verhoef [45] and provides further evidence of the significant role played by emotional factors in relation to pro-environmental consumption behavior [35,92] and organic food purchase [28,93]. It also suggests to the value of incorporating emotional factors like guilt into the TPB for better understanding consumer intention to purchase organic food. Collectively, the findings of this study have highlighted the motivational complexity (including both utilitarian and hedonic motives) of organic food purchase and consumption behavior.

Discussion and Practical Implications
Regarding practical implications, this research has the capacity to facilitate the promotion of positive environmental outcomes by facilitating more effective promotion of organic meat consumption. Organically farmed meat is produced in a much more sustainable manner compared to conventional meat production [20]. This is particularly pertinent in Vietnam where rising meat consumption has been identified as a significant future sustainability issue demanding further investigation in order to reduce associated environmentally detrimental greenhouse gas emissions and excessive natural resources utilization [23]. The greater understanding of organic meet consumption afforded by the research findings can therefore help marketers, policymakers and environmental groups to foster organic food (meat) purchase.
In keeping with recommendations by other researchers [94], the findings of this study can help the Vietnamese government to develop more effective consumer education and Sustainability 2021, 13, 953 11 of 15 information programs. These might include national school education programs regarding the sustainability benefits of organic food consumption to help shape favorable sustainable attitudes and behavior in children.
Effective marketing communication for organic food is also critical in the promotion of more sustainable behavior [94,95] since advertising and communications play such significant roles in determining food product consumption [96]. Also as acknowledged by other studies [97,98] effective integrated multi-media public awareness campaigns offer strong potential for promoting organic food consumption, particularly when used in conjunction with appropriate packaging information and trustworthy certification. These messages and information can be effectively communicated to consumers via appropriate media channels (e.g., TV, radio, internet and social media), in-store brochures and displays.
In terms of communication strategy and message content, given the significance of specific environmental concern, it is important to increase consumer awareness and care for environmental issues nationally. In this regard, joint efforts between the key stakeholders should be made to develop and implement environmental education and communication programs, which provide information and facts about the major problems such climate change, depletion of natural resources and air pollution that Vietnam has been facing. Communication programs should highlight how the production of conventional meat affects animal welfare and the environment in terms of greenhouse gas emissions, land and water utilization and other pollution dimensions. This can trigger the feelings of guilt and regret about purchasing and consuming traditional meat products, which in turn enhance the purchase intention and behavior towards organic meat.
To enhance consumer attitudes towards organic meat purchase, producers and retailers should deliver clear and compelling messages to consumers that organic meat is better for the environment, animal welfare and human health than conventional meat products. They should also communicate that more people are consuming organic foods, and that their family, friends and neighbors are purchasing organic products. This will help increase consumer perception of social norms, which in turn enhances their attitudes towards organic meat purchase.
Given the monetary barriers perceived by consumers to be associated with organic purchases, firms should endeavor to reduce the price of organic meat products by improving production and distribution efficiency. Manufacturers and retailers should also enhance the value perception of organic meat. by strictly adhering to organic agricultural standards, which will help to convince consumers that it is worth paying more for organic meat compared to conventionally produced products.

Conclusions
This study makes a contribution to the growing sustainable food consumption literature and enriches the current knowledge about consumer intention to purchase organic food in developing and emerging markets. It provides support for an extended TPB model to predict organic meat purchase intention in the emerging context of Vietnam. The present study highlights the relevance of incorporating environmental concern and guilt to the TPB factors (i.e., attitudes, subjective norms and perceived monetary barriers) in order to better explain the intention to purchase organic food. It also offers further insights into the rational, emotional and social motivations, as well as monetary barriers, associated with organic food consumption.

Limitations and Future Research Directions
This study, however, has some limitations. First, the sample, while representative of Vietnam's most populous city, is unlikely to be representative of the overall population. Future research should therefore seek to obtain data from both urban and rural consumers in different regions. Second, this study examines only one emotional factor (i.e., guilt), which can be extended in future studies to include other relevant emotional determinants such as fear, empathy and other more positive emotions. Third, although focusing on perceived monetary barriers proved to be effective in explaining organic meat purchase intention, future research can investigate other potential deterrents such as the limited availability of organic products and consumer distrust in organic product labelling. Finally, future research can test the model validated in this study in other contexts, such as organic meat purchases in other emerging markets, consumer intention to purchase plant-based organic food, as well as the wider range of organically grown non-food products.