Introduction
Umami, a term derived from the Japanese word for ‘savoury’(Reference Freeman1), was scientifically introduced as the fifth basic taste in 1985(Reference Hajeb and Jinap2). This flavour was first identified in 1908 by Kikunae Ikeda, who also discovered monosodium glutamate (MSG). MSG is widely used as a flavour enhancer in restaurants, institutional food services, and processed food manufacturing, including frozen meals, canned foods, processed meats, and sauces(Reference Oğuz, Cebeci and Geçici3,Reference Kayode, Bello and Oguntola4) . Its popularity stems from its ability to intensify savoury flavours, making it a favourite amongst consumers and food manufacturers(Reference Reis Rocha, Reis Rocha and Ribeiro5). Moreover, its low cost and lack of stringent regulations allow global food industries to incorporate MSG without hindering international trade(Reference Moldovan, Rusu and Tanase6). The global MSG market was valued at USD 6.60 billion in 2022. It is projected to reach USD 9.2 billion by 2028, with food manufacturing being the largest sector, followed by catering and household cooking(7). This rising demand highlights the growing reliance on MSG in food production(Reference Kayode, Bello and Oguntola4).
Many studies classify MSG as a harmless food additive(Reference Maluly, Arisseto-Bragotto and Reyes8–Reference Sherrell12), as it falls under the category of ‘Generally Regarded as Safe’ by the Food and Drug Administration (FDA)(13). The FDA has not set an acceptable daily intake for MSG, considering it is safe when consumed at normal levels. Generally, a standard serving of food with added MSG contains < 0.5 grams of the additive(13). Further research suggests that high doses of MSG may contribute to metabolic disturbances and neurotoxicity(Reference Zanfirescu, Ungurianu and Tsatsakis14). It should be noted that these claims are often inconsistent due to methodological flaws in studies that used excessive dosing(Reference Freeman1,Reference Aanuoluwapo Adeleke, Abiodun Olajide and Semiloore Omowumi15) . Moreover, distinguishing between naturally occurring glutamate (in tomatoes, cheese) and added MSG (free glutamic acid) complicates the assessment of consumption levels(Reference Zanfirescu, Ungurianu and Tsatsakis14).
The consumption of MSG has sparked global debate, with concerns about long-term health effects given its increasing use(7). Beyond its direct implications, MSG also contributes to the overall sodium intake(Reference Lim16), which is positively associated with systolic and diastolic blood pressure(Reference Shi, Yuan and Taylor17). Hypertension is a leading risk factor for cardiovascular disease, and currently it affects 26% of the world’s population(Reference Crea18) and 29.2% of Malaysia’s population(19). The rapid urbanisation and sedentary lifestyles in Malaysia have led to increased reliance on processed foods, resulting in higher sodium intake and unhealthy dietary habits(Reference Naing, Yeoh and Wai20). Ironically, while MSG has been proposed as a salt substitute due to its two-thirds lower sodium content as compared to table salt(Reference Maluly, Arisseto-Bragotto and Reyes8), its effectiveness in reducing sodium intake remains uncertain.
MSG labelling practices can influence consumer behaviour, impacting their ability to adopt low-MSG diets. Research indicated that the ‘No Added MSG’ labelling has affected consumer purchasing decisions, which prompted leading manufacturers to highlight ‘No Added MSG’ on their products, even when MSG is naturally present(Reference Alias, Mohd Rusli and Than21). Conversely, some manufacturers disguise MSG under alternative labels such as flavour enhancers, monosodium salt, or L-glutamic acid(Reference Sultana Siddiqua22). The Malaysian Food Regulations 1985 mandate proper food labelling, including the declaration of MSG and additives. Non-compliance can result in legal penalties, emphasising the need for regulatory enforcement(23).
Up to now, no market surveys have been conducted on the presence of MSG and its labelling in Malaysian processed foods. Additionally, understanding the association between MSG and other umami enhancers may help in detecting hidden MSG sources in products labelled only as ‘flavour enhancers’. Therefore, this study aimed to examine the presence of MSG in processed foods by identifying the labelling practices used in the Malaysian market, thereby contributing to the development of a comprehensive MSG database. In addition, this study has assessed the sodium level in products with and without MSG, investigated the association between MSG and other umami enhancers in processed foods, and evaluated food manufacturers’ adherence to the MSG declaration requirements outlined in the Food Regulation of 1985. The findings can contribute to policy reviews, enhance nutritional labelling standards, and encourage the reformulation of healthier processed foods in Malaysia.
Methods
Study design and data collection
A cross-sectional market survey to examine the incorporation of MSG in processed foods in the Malaysian market was carried out by using a convenience sampling method between June and September 2021. The study was approved by The National University of Malaysia Research Ethics Committee (code: JEP-2021-583). During the study, the Movement Control Order (MCO) was implemented, necessitating a mixed-method approach that covered both physical and online market surveys. To identify products available in hypermarkets, the physical market survey was initially carried out at operating stores during the MCO(Reference Lim24). The remaining products were supplemented through an online survey.
The selected hypermarkets for the study were Giant and Lotus’s, both of which rank amongst the top 10 grocery stores in Malaysia(Reference Khoo25). Besides, these hypermarkets are located within 10 km from the researcher’s residence, ensuring accessibility amid the movement restrictions. The market survey was conducted by the researcher through multiple visits throughout May 2021. Giant was visited on the 13th, 14th, 15th, and 16th May, while Tesco was visited on 25th, 26th, 27th, 28th, and 29th May. Multiple visits were necessary due to shortened operating hours and limited time for customers to remain inside the hypermarkets. During each visit, one to two product categories were examined, depending on their availability. Gaps between visits were minimised to reduce the likelihood of stock rearrangement from affecting the survey results. Upon completion, all surveyed products were categorised based on their main categories and subcategories.
During the COVID-19 pandemic, the shift in consumer behaviour resulted in an increased acceptance of online grocery shopping. Therefore, the online grocery platforms were essentially included in this study. The approach not only expanded product coverage, and compensated for any limitations in the offline market survey, but also aligned with the changing shopping trends during the lockdown. HappyFresh and Tesco Online were selected for the online survey to supplement missing items and gather additional product information. This selection was based on recommendations from The Citylist(26). Malaysia’s first grocery delivery service HappyFresh, reported a 10- to 20-fold increase in sales since 2020. Through HappyFresh, users could gain access to various hypermarkets, including Aeon and Mydin. HappyFresh Malaysia offers clear product images, while Tesco Online has detailed product information. The online market survey was conducted on 11th, 12th, and 13th June via HappyFresh, and on 16th, 17th, 18th, and 19th June via Tesco Online. Each category was systematically reviewed by using the provided online grocery platforms classification. Products which were recorded during the offline survey were excluded, while new ones were identified and included. The market survey process is demonstrated in Figure 1.
Figure 1. Process of market surveys.
Nutritional information panel, ingredient list, and other extra information printed on the packaging of processed foods were examined in the market survey. As for the physical survey, photographs of the packaging were taken with a phone camera. But, for the online surveys, screenshots of the packaging were saved for record-keeping purposes. Information collected from the food product packaging included name and brand, presence of a ‘No Added MSG’ label, any MSG declared in the ingredient list, alternative names used to identify MSG, presence of other umami flavour enhancers, and the sodium content expressed in mg/100 g.
When identifying products that contain MSG in the ingredient list, its alternative names were also considered. The possibility that manufacturers might label MSG in both English and Bahasa Malaysia were also taken into account. This included the chemical name (Monosodium Glutamate, MSG, Mononatrium Glutamat, Monosodium Glutamat), the functional class (Permitted Flavour Enhancer, Flavour Enhancer, Bahan Perisa yang dibenarkan, Bahan Perisa), as well as the identification number system (INS 621, E621), or a combination of any of these terms (Table 1).
Table 1. Common method of MSG declared
Product selection and categories
All processed food products available in the market were included, regardless of their country of origin. Both locally produced and internationally manufactured processed foods available in hypermarkets were considered to ensure a comprehensive coverage of all processed foods accessible to Malaysian consumers. Processed foods are defined as those that had undergone modifications such as washing, cutting, heating, pasteurising, cooking, canning, freezing, drying, mixing, or packaging(27). Unprocessed or minimally processed (plain) foods, including those without added oils, free sugars, sweeteners, or salt(Reference Haron, Hiew and Shahar28), were excluded from the study.
Food products were classified based on the FAO/WHO Food Standards CODEX Alimentarius: Food Categories.(Reference Haron, Hiew and Shahar28). As shown in Table 2, seven main categories were adopted: fruits and vegetables (Code 04.0), cereal and cereal products (Code 06.0), meat and meat products (Code 08.0), fish and fish products (Code 09.0), salts, spices, soups, sauces, salads, protein products (Code 12.0), ready-to-eat savouries (Code 15.0), as well as prepared foods (Code 16.0).
Table 2. Classification of products according to FAO/WHO Food Standards CODEX Alimentarius
Statistical analysis
Statistical analysis was conducted using the Statistical Package for Social Sciences version 23.0 software. Descriptive analysis was utilised to analyse the data, whereby frequency, percentage, mean and standard deviation were used. For each main category and subcategory, the total number and percentage of products which incorporated MSG were calculated. Next, the mean and standard deviation of sodium levels amongst products were calculated. Furthermore, the number and percentage of products that accurately declared MSG in the ingredient list, indicated the ‘No Added MSG’ description, included sodium and sugar labelling, as well as other umami flavour enhancers were recorded. Non-parametric tests were conducted because the analysed data were not normally distributed. Mann-Whitney U-test was done to compare the mean sodium levels between products with and without MSG, while the Chi-Square test was used to test the association between the presence of MSG and umami flavour enhancers. The significance level was set at 0.05, whereby p < 0.05 was reported to be statistically significant.
Results
Presence of MSG in products
Figure 2 depicts the number and percentage of products with and without MSG across various categories. A total of 547 products (50.8%) were found to contain MSG. Amongst the main categories, ready-to-eat savouries (Code 15.0) had the highest percentage of MSG-containing products (60.2%), followed by fish and fish products (Code 09.0) at 57.8%, and cereals and cereal products (Code 06.0) at 55%. Conversely, fruits and vegetables (Code 04.0) had the lowest percentage at 19.4%.
Figure 2. Presence of MSG in main categories and subcategories.
At the subcategory level, instant noodles (soup) (Code 15.3) contained the highest percentage of MSG-containing products at 96.9%, followed by fish-based snacks (Code 15.3) at 93.3%, and mixes for soups and broths (Code 12.5.2) at 91.3%. In contrast, Western meals had only 7.1% of MSG-containing products.
Sodium level (mg/100 g) of processed food products
Figure 3 illustrates the sodium level (mg/100 g) in products with and without MSG. Due to the small sample size (n < 5), comparisons could not be conducted for fruits and vegetables (Code 04.0), cereals and cereal products (Code 06.0), as well as meat and meat products (Code 08.0). Overall, MSG-containing products had a significantly higher mean sodium level (2812.2 ± 5191.4 mg/100 g), with a difference of 1440 mg as compared to those without MSG (1372.2 ± 1541.4 mg/100 g) (p < 0.001). In particular, food categories containing MSG, including salts, spices, soups, sauces, salads, and protein products (Code 12.0) (p < 0.001), ready-to-eat savouries (Code 15.0) (p = 0.006), and prepared foods (Code 16.0) (p < 0.001) demonstrated significantly higher sodium level as compared to their MSG-free counterparts. Amongst the MSG-containing products such as salts, spices, soups, sauces, salads, and protein products (Code 12.0) had the highest mean sodium level at 5605.7 ± 7522.0 mg/100 g. In contrast, fish and fish products (Code 09.0) had the lowest mean sodium level amongst MSG-containing products, measuring 576.3 ± 200.7 mg/100 g.
Figure 3. Sodium level (mg/100 g) of savoury food products with and without MSG.
Association between MSG and flavour enhancer
As shown in Table 3, 57.5% of MSG-containing products also simultaneously contained other flavour enhancers, such as yeast extract, disodium inosinate (IMP), and disodium guanylate (GMP). A significant association was observed between the presence of MSG and other flavour enhancers (p < 0.001). Specifically, this significant association was evident in food categories such as fruits and vegetables (Code 04.0) (p = 0.004), salts, spices, soups, sauces, salads, and protein products (Code 12.0) (p < 0.001), ready-to-eat savouries (Code 15.0) (p < 0.001), and prepared foods (Code 16.0) (p < 0.001).
Amongst processed products, a notable 75.9% of products contained both MSG and other flavour enhancers, whereas 24.1% contained only other flavour enhancers without MSG. In contrast, all (100%) fruits and vegetables (Code 04.0) without added flavour enhancers did not contain MSG. Conversely, fish and fish products (Code 09.0) had the highest percentage of MSG-containing products at 84.8%.
Table 3. Association between the presences of MSG against the presence of flavour enhancers for each main category
*Chi-square test was used to test Presence of MSG against Presence of flavour enhancers for each category and total items surveyed.
Presence of ‘No Added MSG’ description among processed foods without MSG
As shown in Table 4, amongst the 529 products without MSG, 75 (14.2%) were labelled as ‘No MSG Added’. Cereal and cereal products (Code 06.0) had the highest percentage of this label (55.6%), followed by meat and meat products (Code 08.0) at 36.8%, and prepared foods (Code 16.0) at 15.3%. In contrast, fish and fish products (Code 09.0) had no products (0.0%) labelled with the ‘No MSG Added’ claim.
Table 4. Presence ‘No MSG Added’ description among products without MSG
Additionally, among the 547 processed MSG-containing foods, 61% accurately declared its presence in accordance with the Food Regulation 1985 (23), labelling it as ‘Contains Permitted Flavour Enhancers’. Many of these products also included additional labelling information, explicitly stating, ‘Contains Monosodium Glutamate as Permitted Flavour Enhancers’.
Discussion
To the best of knowledge, this is the first market survey which examined the presence of MSG in processed foods sold in Malaysia’s hypermarkets and online platforms. By analysing 1076 products, a comprehensive overview of MSG usage in the local market was provided, laying the foundation for further research in food composition and reformulation. This finding is a concern, as ultra-processed foods are often high in sugar, saturated fats, and sodium, while often being low in fibre and essential micronutrients(Reference Martini, Godos and Bonaccio29).
The study found that MSG-containing products had higher sodium levels than those without, contradicting the notion that it can reduce overall sodium content by replacing added salt(Reference Maluly, Arisseto-Bragotto and Reyes8). This finding is aligned with previous studies suggesting that the optimal palatability of processed foods requires sufficient salt in combination with umami substances such as MSG(Reference Yamaguchi and Kimizuka30,Reference Yoshida and Ninomiya31) . Furthermore, flavour synergy is achieved when MSG is paired with nucleotide flavour enhancers, such as IMP, GMP, and yeast extract(Reference Rocha, Ribeiro and Silva32). Therefore, the high sodium content in processed foods may be attributed to the combined presence of salt, MSG, nucleotide flavour enhancers, and other sodium-containing food additives used for preservation and texture enhancement(33).
A prior cross-sectional market survey conducted in Malaysia focused exclusively on the sodium content of sauces sold in supermarkets. This earlier research found that fish/prawn sauces contained the highest sodium levels(Reference Shahar, You and Zainuddin34). In contrast, the present study reported that fish-based processed foods (Code 09.0) had the lowest MSG content. This finding further supports the notion that products naturally high in glutamate, such as fish-based products rely more on added salt than MSG to enhance palatability(Reference Yamaguchi and Kimizuka30).
Another local study on street foods reported that snacks contained the highest sodium levels (433 mg), followed by main meals (336.5 mg), with sauces contributing significantly to this sodium content(Reference Haron, Zainal Arifen and Shahar35). Similarly, this study found that ‘salts, spices, soups, sauces, salads, and protein products’ had the highest sodium levels, particularly in MSG-containing products. This reinforces the critical role of both salt and glutamate in maximising flavour in processed foods(Reference Panzarini, Menis-Henrique and Conti-Silva36). While the street food study had primarily focused on ready-made or ready-to-eat foods(Reference Haron, Zainal Arifen and Shahar35), this study takes a broader approach by encompassing both ingredients and processed products. Therefore, this study offers a broader perspective as various products used in different occasions and preparation stages were included.
The present study revealed that MSG contributed significantly to sodium levels in the diet. While MSG is widely used, the results indicated that its role as a salt substitute in processed foods is not as effective as commonly believed. These findings emphasised the need for consumers to limit ultra-processed foods and choose fresh, low-sodium alternatives particularly for sodium-sensitive groups, such as individuals with hypertension or kidney disease. This is in line with Key Message 6 of the Malaysian Dietary Guidelines 2020(37), which advocates for selecting and preparing foods with less salt, sauces, and flavour enhancers. In summary, until the potential risks associated with excessive MSG intake are confirmed, the concern should be the dangerously high sodium levels found in processed and outside foods. Healthcare professionals, including dietitians and nutritionists, play a key role in educating the public about the distinction between minimally processed nutritious foods and ultra-processed products high in umami flavouring. Policymakers should strive to increase awareness amongst both consumers and manufacturers regarding the importance of controlling blood pressure through sodium level management. More time and resources should be invested in research to develop palatable foods that do not require excessive use of salt or other food additives that could increase the sodium levels in processed or outside foods.
Food labelling remains a critical issue due to the potential confusion arising from non-standardised ingredient declarations, especially for consumers sensitive to MSG. In Malaysia, there are no specific regulations governing the use of ‘No MSG Added’ claims, which can result in misleading labelling practices(Reference Alias, Mohd Rusli and Than21). A study by Shim et al. found that 17.4% of respondents relied on food packaging for product information, while 58% obtained information primarily through food labels(Reference Shim, Seo and Lee38). Consumer perceptions of food risks and benefits are heavily influenced by their knowledge of regulations and trust in authorities(Reference Ngo, Phan and Le39). This study found that only 61% of products correctly declared the presence of MSG, and 14.2% of MSG-free products carried a ‘No MSG Added’ label, potentially misleading consumers about the presence of other sodium-based additives. The ‘No MSG Added’ claim serves as a powerful marketing tool because many consumers tend to favour products that are perceived to be MSG-free(Reference Alias, Mohd Rusli and Than21). Manufacturers may leverage this demand as a marketing strategy, as consumers associate these products with premium quality and better health benefits(Reference Maluly, Arisseto-Bragotto and Reyes8).
According to the Food Regulation 1985(23), flavour substances must be declared under their functional class. However, the use of multiple declaration methods can be confusing, particularly for imported products with foreign labelling. Despite the lack of strict regulations, most manufacturers have taken the initiative to provide additional labelling information, including the full name of MSG and its INS number (INS621; E621), which can improve consumer awareness. This practice reduces the barrier for consumers to identify MSG on ingredient lists. However, inconsistencies in labelling persist across brands, and global trade names for sodium glutamate vary(Reference Sultana Siddiqua22). Therefore, policymakers should align Malaysia’s food additive declaration requirements with international standards to ensure consistency and facilitate global trade.
Consumer awareness and education are crucial in addressing these issues. Food labelling remains an essential tool for consumers to make informed dietary choices. The Malaysian Dietary Guidelines 2020(37) emphasise the importance of reading and interpreting food labels to make healthier dietary choices (Key Message 14). The study findings highlight the urgent need for stricter regulations on the use of this claim to prevent misleading marketing practices, as well as enhance public education initiatives. These efforts are essential to empower consumers in accurately assessing nutrition labels and make informed buying decisions.
However, this study has several limitations. Firstly, the study used convenience sampling based on product accessibility during the COVID-19 Pandemic’s movement controlled order (MCO), which may limit generalisability due to potential selection bias and underrepresentation of products from other regions or retail settings. Future studies should consider using a more systematic sampling approach to better represent a wider variety of products from different regions and retail settings. Besides, sodium content and MSG presence were determined solely from food packaging labels, highlighting the need for direct food analysis in future studies to ensure accuracy. Next, data collection occurred during a pandemic lockdown, which restricted the number of hypermarkets surveyed. To enhance the coverage, online stores were also included; however, these platforms tend to offer a wider variety of imported products, potentially influencing the findings. Further research is needed to quantify sodium contributions from MSG against other food additives through direct food analysis. Moreover, future studies could explore how MSG-containing processed foods impact blood pressure across different age groups, enabling healthcare professionals to provide targeted dietary recommendations. As online shopping continues to gain traction in Malaysia, market surveys focusing on e-commerce platforms could provide deeper insights into consumer trends and labelling practices in the digital marketplace.
Conclusions
This market survey demonstrated that approximately half of the processed foods sold in the Malaysian market incorporate MSG, with ready-to-eat products and instant noodles topping the list. The study also highlighted concerns over the high sodium levels in MSG-containing processed foods and the poor adherence to MSG labelling regulations. To address these issues, it is essential to strengthen regulatory enforcement, promote accurate food labelling, and encourage the food industry to reformulate products with reduced sodium content. Additionally, public education on nutrition labels should be intensified to help consumers make informed choices. Future research should focus on analysing actual MSG and sodium content in foods and exploring alternative sodium reduction strategies to support public health initiatives.
Acknowledgments
Not applicable.
Author contributions
All authors have participated in the process of in critical revision of the manuscript for optimum intellectual content. JYC drafted the manuscript and edited by SS and YQO. JYC involved in data collection, data analysis and data interpretation. SS were involved in conceptualising and designing the study, advised on data collection. HH advised on study design, food labelling and food classification. All authors have read, edited and approved the final draft of this manuscript.
Financial support
This research was partially supported by the Newton Fund Impact Scheme by the Medical Research Council on behalf of UK Research and Innovation in the United Kingdom (NN-2020-082).
Competing interests
The authors declare that they have no competing interests.
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