Chocolates may be regarded as the world’s most popular snack food. An average American consumes over 4kg of chocolate annually, while in Switzerland, the world’s leading chocolate producer, a Swiss consumes over double this amount. Indians also have a sweet tooth, and consume considerable amount of sweets, including chocolates.
However, it has recently come to light that chocolates can become contaminated, in spite of the fact that it has been consumed for centuries without any complaint of any apparent ill effect. Some of these contaminants are discussed below.
Heavy Metal Contamination
It might sound surprising, but heavy metal contamination can be a problem in case of chocolates too! Since cocoa powder is the key ingredient for making chocolates, the Food Safety and Standards Authority of India (FSSAI) has fixed the upper permissible levels for two heavy metals. These are lead and copper. As per the Food Safety and Standards (Contaminants, Toxins and Residues) Regulations, 2011, the maximum permissible levels of these heavy metals in cocoa powder are as follows:
- Lead : 5.0 ppm by weight, on the dry fat-free substance
- Copper : 70 ppm by weight on the fat-free substance
A recent study in California, USA conducted by a non-profit organization indicated that out of 42 chocolate products tested, 26 (62%) contained lead and/or cadmium above permissible levels as stipulated in California’s so-called “Proposition 65 law”. The offending companies included leading brands like Hershey, Mars, Godiva and others. It is important that consumers should know that the chocolates that they eat could be contaminated with heavy metals, so that they can make better informed choices.
- Lead exposure can cause damage to the central nervous system (CNS), leading to learning difficulties and lower IQ in infants and young children.
- Lead is dangerous for pregnant women.
- Cadmium exposure must be avoided by pregnant women and children.
- Cadmium is carcinogenic, and causes damage to the kidneys, bone and liver.
- Children are more susceptible to chronic exposure to low levels of cadmium through the oral route.
- Copper exposure can cause general weakness, hypothyroidism, depression, constipation and low blood pressure, amongst other symptoms.
Interestingly, a 2005 study by the University of California, Santa Cruz found that the average lead concentration of cocoa beans was </= 0.5 ng/g, which is one of the lowest reported values for a natural food. In contrast, lead concentrations of manufactured cocoa and chocolate products were as high as 230 and 70 ng/g, respectively, which was among the highest reported for all foods. Therefore, it is during transportation and processing of the cocoa beans during chocolate manufacture that the major contamination occurs, and not from the soil, as is commonly assumed (Rankin et al., 2005).
Enteric Bacterial Contamination
Enteric bacteria such as Salmonella and coliforms such as Escherichia coli have been found to be a significant source of contamination of chocolate. A recent survey conducted in two Brazilian chocolate manufacturing companies analysed different chocolate types, processed cocoa-based ingredients, manufacturing environment, and workers’ hand surfaces to investigate Enterobacteriaceae, coliforms and Salmonella contamination (Nascimento et al., 2015).
- The study identified the source of Enterobacteriaceae contamination in chocolate. Enterobacteriaceaewere isolated from 26% of chocolate samples, while total coliforms detected in 13% of samples.
- Cocoa-based ingredients were not a significant contamination source in chocolate.
- Enterobacteriaceaewere detected in 25% of the equipment and utensils tested, whereas total coliforms were detected in 10%.
- In one company, 14% of manufacturing environment samples were contaminated by thermotolerant coliforms.
- The food handlers from both companies showed a high percentage of Enterobacteriaceaecontamination on their hands.
Conclusion: Manufacturing environment including food handlers were the most likely Enterobacteriaceae contamination source of chocolates. Therefore, Enterobacteriaceae are a good hygiene indicator for the chocolate industry.
Contamination with Insect & Rodent Filth
Contamination with insect and rodent filth can sometimes be a problem, especially during storage and transportation of the raw materials such as cocoa powder. These types of filth usually include insect body parts and rodent hair. If these are transferred during the chocolate making process, they can be a health hazard. Therefore, it is of the utmost importance to maintain quality control during the entire manufacturing process.
Intentional Adulteration of Chocolates
It has come to light that in recent years, the amount of adulteration of traditional sweets increases with increase in demand, especially during festival times like Diwali. With changing preferences in distribution of sweets during festivities, chocolates have become the latest snack food items to be adulterated. Some unscrupulous businessmen intentionally carry out adulteration of chocolates to increase their profit margin. Some of the ways that adulteration of chocolates can be carried out intentionally, include:
- Using inferior quality sugar for manufacturing chocolates.
- Adding minerals to increase the weight of the chocolates.
- Adding starch during manufacture of chocolates.
- Using non-permitted artificial colouring.
The Way Forward
The foregoing discussion is an eye-opener, as the world’s most favourite snack food has even not been spared from adulteration. Therefore, it is important that stringent quality checks be put in place along the entire chain in the manufacturing process of chocolates. This is very important as chocolates are consumed in large quantities by children and adults around the globe. The health and wellbeing of young children is of the highest priority. Stringent quality control will ensure that the chocolates that are consumed by with millions of people are wholesome and nutritious food items that are safe to consume.
- Rankin CW, Nriagu JO, Aggarwal JK, Arowolo TA, Adebayo K, Flegal AR. Lead contamination in cocoa and cocoa products: isotopic evidence of global contamination. Environ Health Perspect2005; 113(10): 1344-8.
- Nascimento MS, Reolon EM, Santos ARB, Moreira VE, Silva N. Enterobacteriaceaecontamination in chocolate processing. Food Control 2015; 47: 291-7.