Skip to main content

60% of Peanut Butter Samples Detected with Liver-damaging Aflatoxins With 2 Exceeding EU Limit High in Fat and Excessive Consumption Could Cause Obesity Despite Containing Nutritious Unsaturated Fatty Acids

  • 2023.11.15

Peanut butter is considered by many as a perfect match for bread and toast. Not only is it tasty, but it also contains unsaturated fatty acids (UFAs) which provide nutrients and calories required by the human body. However, according to the Consumer Council’s test on 20 samples of peanut butter which are relatively popular in the market, 60% were detected with aflatoxins, which could damage liver function, while the aflatoxin B1 levels of 2 samples exceeded the upper limit of European Union (EU) standards. Test results also revealed that although peanut butter contains healthy unsaturated fatty acids, 95% of the samples were classified as “high fat” food, which could lead to obesity and increase the risk of cardiovascular diseases if consumed in excess over a prolonged period. Consumers are advised to pay attention to the serving size and enjoy in moderation. In addition, the declared values on nutrition labels of some samples were inaccurate, with a highest difference of 5.5 times compared with the actual content, thus consumers may not be able to acquire the correct nutritional content of the products. The Council urges relevant product manufacturers to pay attention and impose measures to correct the issue promptly.

The Council sourced 20 peanut butter samples for testing, including 10 crunchy and 10 creamy peanut butters. The price of the samples varied considerably, ranging from $3.9 to $21.3 per 100g, a difference of nearly 4.5 times. Test items included aflatoxins (B1, B2, G1 and G2), heavy metal cadmium, plasticisers, preservatives, and the pathogen Salmonella spp. The total fat, saturated fatty acids (SFAs), trans fatty acids (TFAs), unsaturated fatty acids (UFAs), sugar and sodium contents were also tested, while the nutrition labelling information on the package of the products was reviewed for consistency with test results. In terms of overall rating, 3 samples received the highest score of 4.5, with prices ranging from $9.5 to $19.7 per 100g, while the lowest score of 2 was given to 1 sample, priced at $20.3 per 100g, indicating that there is no direct correlation between the price and product quality.

Aflatoxins Detected in 2 Samples Exceeded EU Limit

Aflatoxins could cause acute and chronic poisoning in animals and humans, and could lead to acute liver damage, cirrhosis, cancer and even death. Aflatoxins cannot be broken down easily in the normal cooking process, and among them, aflatoxin B1 is classified as a human carcinogen (Group 1). Test results showed that 12 samples were detected with aflatoxins at levels ranging from 0.23µg/kg to 4.94µg/kg, none of which exceeded the requirement stipulated in the Harmful Substances in Food (Amendment) Regulation 2021, which states that no more than 10µg aflatoxins should be present in each kg of food. However, based on per kg, 2 samples contained aflatoxin B1 at levels of 4.27μg and 2.01μg respectively, which exceeded the EU limit of 2.0μg, among which the total aflatoxins level of 1 sample (4.94μg) also exceeded the EU limit of 4.0μg.

95% Samples High in Fat

Excessive Consumption May Lead to Obesity and Cardiovascular Diseases

An appropriate amount of fat intake could provide the body with sufficient calories and essential fatty acids, but excessive intake would lead to obesity and increase the risks of heart disease and diabetes. According to the Centre for Food Safety (CFS), a food item containing more than 20g of total fat per 100g of food is considered as “high fat”. Based on the content per 100g, aside from 1 sample, the rest were all classified as “high fat”, with total fat contents ranging from 37.9g to 52.8g. The sample not classified as “high fat” contained 12.9g of total fat and could neither be classified as a “low fat” food (not more than 3g of total fat per 100g of solid food) as defined in the Food and Drugs (Composition and Labelling) Regulations (“Composition and Labelling Regulations”). The World Health Organization (WHO) recommends a fat intake of 15% to 30% of the body’s daily energy requirement. For example, a 60kg adult with an energy intake of 2,000kcal/day and a 6-year-old girl consuming 1,450kcal/day should consume less than 66g and 48g of total fat per day respectively. Taking the sample with the highest total fat content (52.8g per 100g) as an example, a single serving (32g, 2 tablespoons) is equivalent to an intake of about 16.9g of fat, which is already about 26% and 35% of the recommended daily intake for an adult and a 6-year-old girl respectively.

Both SFAs and TFAs increase the amount of bad cholesterol in the blood and increase the risk of cardiovascular diseases with prolonged and excessive intake. The average SFAs content of all samples was 8.92g per 100g, with the highest sample containing 13.62g. An adult consuming a serving of this sample (32g) would have an intake of about 4.4g of SFAs, which is about 20% of the daily intake limit (22.2g) recommended by the WHO. In addition, TFAs were detected in half of the samples, with levels ranging from 0.11g to 0.19g per 100g. Based on the sample with the highest TFAs content, an adult consuming 1 serving (30g) would have a TFAs intake of about 0.057g, which would account for about 2.6% of the maximum daily intake limit recommended by the WHO for adults (2.2g).

Monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) help to reduce bad cholesterol in the blood and also lower total cholesterol levels. Appropriate levels of PUFAs help develop the skin, retina and brain nerves of foetuses and developing children. Among the 20 samples, a difference of around 6 times was found between the highest and lowest MUFAs content, while that for PUFAs was about 7 times. Consumers should note that although UFAs are beneficial to the body, they are still fats and prolonged excessive consumption over a long period of time could also lead to weight gain.

Sugar Content Varied Greatly So Choose with Care

Like fat, sugar provides calories for the body, but excessive intake could increase the risks of tooth decay, overweight, obesity and diabetes. According to the Composition and Labelling Regulations, food containing less than 5g of sugar per 100g is considered “low sugar”, while according to the CFS, food containing more than 15g of sugar per 100g of solid food is considered “high sugar”. Based on the content per 100g, 1 sample was classified as “high sugar” with a content of 28.2g. Consumption of 1.5 tablespoons (24g) would incur an intake of about 6.8g sugar, which accounted for about 13.6% and 18.9% of the recommended upper limit of daily intake of sugar for an adult and a girl of 6 years old respectively. For the 3 samples classified as “low sugar” food, the sugar content ranged from 4.0g to 4.6g, which varied by around 5 to 6 times compared with the sample with the highest sugar content.

8 Samples with Nutrition Labelling Variance Exceeding Tolerance Limit

Improvements Urged

All prepackaged food products sold in Hong Kong are required to be labelled with relevant nutrition information, but some samples were found with considerable variances between their labelled values and actual test results. Among them, 4 samples were found with a variance between their actual and labelled SFAs contents ranging from 23.9% to 94.6%, which exceeded the tolerance limit (≤ 120% of the declared value). Additionally, 3 samples had variances between the actual and labelled sodium and sugar contents exceeding 20%; the variance for sugar ranged from 26% and 74.2% among the 3 samples, while that for sodium ranged from 42.2% to a whopping 551%. Furthermore, 1 sample did not have any indication of TFAs and sugar content, and another sample displayed 2 ingredient lists and 2 weight labels, which could be confusing for consumers.

In addition, according to the Composition and Labelling Regulations, nutrient content claims can only be made in respect of energy or nutrients specified in the conditions relating to nutrient content claims in Schedule 8 of the Composition and Labelling Regulations and must comply with all relevant conditions set out in Schedule 8, and monounsaturated fatty acid is not listed in Schedule 8. Therefore, food products are not allowed to carry such nutrient content claims. However, the package of 1 sample was labelled “high in monounsaturated fats”.

The Council has referred the information of relevant samples to the CFS for follow-up.

Consumers are advised to pay attention to the following tips when purchasing and consuming peanut butter:

  • Check the product description on the packaging and pay attention to the ingredients. Choose products without added salt and sugar, and with peanuts listed higher on the ingredient list, which means that peanuts account for a relatively larger proportion of the ingredients. In addition, choose products with more protein and unsaturated fatty acids and less SFAs, TFAs, sugars, and sodium;
  • Check the shelf life and expiry date, and store in a cool and dry place away from direct sunlight. Peanut butter should be stored in the refrigerator after opening and used up within 2 to 3 months;
  • If peanut butter appears to have oil separation, perhaps due to prolonged storage, use a clean spoon to mix well before consumption. If the peanut butter tastes rancid, the product has gone bad and should be discarded immediately.


Download the article (Chinese only):


Consumer Council reserves all its right (including copyright) in respect of CHOICE magazine and Online CHOICE.