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ISSN : 1229-1153(Print)
ISSN : 2465-9223(Online)
Journal of Food Hygiene and Safety Vol.32 No.4 pp.254-261
DOI : https://doi.org/10.13103/JFHS.2017.32.4.254

Monitoring of the Source of Gelatin in Dietary Supplement Capsules Sold on the Internet

Tae Sun Kang
*, Mi-Ra Kim
, Yewon Hong
, Jae-Hwang Lee
, Kisung Kwon
New Hazardous Substance Team, Food Safety Evaluation Department, National Institute of Food and Drug Safety Evaluation, Ministry of Food and Drug Safety, Cheongju, Korea
Correspondence to: Tae Sun Kang, New Hazardous Substance Team, Food Safety Evaluation Department, National Institute of Food and Drug Safety Evaluation, Ministry of Food and Drug Safety, 187 Osongsaengmyeong 2-ro, Osong, Cheongju 28159, Korea 82-43-719-4454, 82-43-719-4450missa@korea.kr
20170615 20170704 20170625

Abstract

Determining the origin of the components in commercially available gelatin, a purified protein derived mostly from pig skin and bovine tissue, is a challenge, leading to concerns on the grounds of religious beliefs and health. Therefore, regular monitoring of labeling compliance by food control authorities is also necessary. In this study, we monitored the origin of gelatin capsules from 181 commercial dietary supplements that were available for purchase on the internet, using species-specific PCR assays. Fifty five products were labeled correctly, declaring that they used bovine-, fish- and plant-derived gelatin, whereas the other 126 capsules were labeled “gelatin” without specifying the origin. Gelatin in these capsules was obtained from cattle (n = 51), pigs (n = 31), or both (n = 44). Therefore, it is important to declare all of the raw materials used to produce gelatin capsules on the labels to best protect consumers’ rights, religious beliefs, and health.


초록


    Ministry of Food and Drug Safety
    16161MFDS057

    In South Korea, capsules are defined by the Korean Food Code1) as a type of food formulation containing gelatin, glycerin, and other additives. Gelatin is one of the major constituents in a wide range of food products, pharmaceutical medicine capsules, and cosmetics. The majority of edible gelatin is obtained by the hydrolysis of collagen extracted from bovine and porcine hide and splits. The production of gelatin involves several processing steps, including the acidic or basic hydrolysis of raw materials, high-temperature and high-pressure extraction with water, sterilization, and drying. Hence, determining the origin of commercially available gelatin is a challenge. Moreover, only a few studies have focused on the identification of the origin of gelatin, gelatin-containing foods, and capsule shells2-4). Therefore, the variation and accuracy of the components of gelatin products and the labels remains unknown, posing a threat to consumer rights and manufacturer transparency.

    Various dietary supplements (vitamins, minerals, and herbal products) manufactured by either Korean or foreign companies can be easily purchased over the internet; thus, their popularity has increased for the improvement of general immunity and self-treatment of diseases. This rise in the consumption of gelatin capsules has raised concerns from the point of view of health and religious beliefs2,3,5,6). Dietary supplement capsules are most commonly composed of gelatin obtained from cattle, pigs, fish, or plants. Therefore, the information about the source of gelatin provided in the label can be classified into three groups: (i) mammalian origin, labeled “gelatin”, without specifying the source species; (ii) fish origin, declared as marine or fish gelatin; and (iii) plant origin, labeled hydroxypropyl methylcellulose (HPMC) or vegetarian gelatin. Consumers must rely on accurate labeling information provided by the manufacturers to identify the raw materials used in the production of the gelatin capsules, which is particularly critical for certain consumers such as vegetarians, Muslims, and Hindus, because the consumption of certain food items is prohibited by their religion2,3,5,7). However, some dietary supplements are simply labeled “gelatin”, without identifying the source, which deprives consumers from the sufficient information needed to protect their religious beliefs or their rights to know and choose what they want to eat. Therefore, verifi- cation of labeling compliance can help to protect consumer rights and beliefs, and enhance their confidence in gelatinbased products.

    We previously developed specific polymerase chain reaction (PCR) assays to determine the origin of gelatin in capsules, and reported the successful verification of the labeling compliance of gelatin capsules sold as dietary supplements8). These assays can be used to accurately identify whether the source of gelatin is cattle, pigs, fish, or plants. In the present study, we used these assays to monitor the origin of 181 commercially available gelatin capsules sold via the internet as health supplements and verified their labeling.

    Material and Methods

    Samples

    A total of 181 different commercially available gelatin capsules, marketed as health supplements, manufactured by American (n = 166), Canadian (n = 11), Norwegian (n = 3), and Korean (n = 1) companies, were purchased via the internet. The gelatin capsules were categorized into five groups according to their labeling information: gelatin (n = 126), plant gelatin (n = 37), bovine gelatin (n = 12), halal and/or kosher gelatin (n = 4) and fish gelatin (n = 2).

    DNA extraction and whole-genome amplification

    DNA from these capsules was extracted as described previously by Lee et al.8). To obtain a larger quantity of DNA from the gelatin capsules, DNA extracts were amplified using the GenomePlex® Whole Genome Amplification (WGA) kit (Sigma-Aldrich, St. Louis, MO, USA) according to Lee et al.8).

    PCR amplification and detection

    The information about the primer sets for bovine, porcine, fish, and plant gelatin is provided in Table 1. PCR amplification was conducted as previously described by Lee et al.8), and the amplified fragments were analyzed by 2.0% agarose gel electrophoresis.

    Results and Discussion

    Of the 181 gelatin capsules investigated in this study, the labels of 126 products contained the word “gelatin” but did not specify its source. The labels of the remaining 55 dietary supplements provided detailed information about the source of gelatin, specifying fish (n = 2, fish or marine gelatin), plant (n = 37, HPMC, modified food starch, cellulose, or vegetarian gelatin), bovine (n = 12, bovine) or halal and/or kosher (n = 4) as the source. The identification of different materials in the capsules as detected using the speciesspecific PCR assays is listed in Table 2. Positive results were detected with the plant universal PCR assay for all the 37 samples that declared plant sources as the raw material for gelatin on their labels. Fish DNA was detected with the fish universal PCR assay in the two capsules whose labels mentioned marine and fish gelatin. In 12 samples declared using 100% bovine material, pig and fish DNA was not detected. In addition, our PCR assay demonstrated that two capsules labeled as halal and kosher were plant gelatin, and two kosher capsules were either bovine or plant gelatin. Thus, our results suggest that there is generally good consistency between the labeling information provided by manufacturers and the actual ingredients used to make the capsule. However, we could not confirm the labeling compliance for the remaining 126 capsules because of the limited information provided about the raw materials. As shown in Table 2, these 126 gelatin capsules of unknown source were positive in the bovine-specific and/or porcine-specific PCR assays, suggesting that the gelatin in these capsules was obtained from cattle (n = 51), pigs (n = 31), or both (n = 44). In our previous study, we found that plant-specific products were amplified from the capsules that were labeled to contain gelatin as well as fish gelatin; these plant sources originated from the various plant-derived materials used during the capsule manufacturing process, such as plasticizers to help produce the capsule shape8).

    Gelatin is a popular ingredient (e.g., as a gelling and foaming agent) in the food industry and is widely used in the manufacturing of hard and soft capsules in the pharmaceutical industry2,3). The global market size for gelatin was 412,700 tons in 2015, which is largely attributed to consumption in food & beverage and pharmaceutical applications, accounting for 29.0% and 20.7% of the global volume in 2015, respectively9). In Europe, approximately 80% of the edible gelatin is produced from pure pig skin, 15% comes from cattle hide split, and the remaining 5% comes from pig and cattle bones as well as fish10). Therefore, strong concerns remain among consumers with religious beliefs that proscribe the consumption of certain food items. For example, Judaism and Islam forbid the consumption of porcine products, whereas Hindu customs do not permit the consumption of bovine products. In addition, Buddhists are strict vegetarians and are prohibited from eating mammalian products5-7). Therefore, the identification of the raw materials used to make gelatin is critically important from a regulatory point of view and will help instill confidence in the end user. Although the food labeling regulations of South Korea make it compulsory to declare all raw materials or ingredients on the labels of packaged foods in an accurate and transparent manner11), determining the origin of commercially available gelatin is still a challenge owing to the multiple processing and purification steps involved in its production. In this study, we did not observe any cases of mislabeling or substitution of the source of gelatin in the capsules. However, among the capsules analyzed in this study, only 30% declared that bovine-, fish- or plant-derived gelatin was used. The majority (70%) of dietary supplement labels did not specify the species used as the raw material for gelatin production. Such inadequate labeling would result in serious consequences such as violation of religious beliefs and health concerns (e.g., bovine spongiform encephalopathy). With respect to religious faiths, it is particularly important to inform consumers about products that might contain traces of pork and/ or beef on the labels. Therefore, we suggest that capsules labeled with simply the item “gelatin” without identifying the source of the protein should further declare the raw material used to best protect consumers’ rights and religious beliefs. Providing sufficient information about the source of gelatin would likely boost consumers’ trust in gelatin-based products, especially in the vegetarian, halal, and kosher markets, which in turn can promote the industry.

    Acknowledgements

    This study was supported by a grant (16161MFDS057) from the Korean Ministry of Food and Drug Safety.

    Figure

    Table

    Primers used in this study

    Identification of raw materials of gelatin capsules by species-specific PCR

    1)HPMC : hydroxypropyl methylcellulose

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