How NGS is taking control of herb and spice fraud once and for all

June 2021

By their very nature, herbs and spices are vulnerable to adulteration, and the problem has only been compounded by the pandemic.

But next generation sequencing is giving food manufacturers, retailers, and regulators, the tools they need to finally call time on food fraud.

Earlier this year, Spanish authorities swooped on an organised criminal group, arresting 17 people and seizing tens of thousands of euros in cars, gold, jewellery, and cash. But these were not drug traffickers or currency counterfeiters – they were trading in adulterated saffron.

The group imported the spice from Iran before mixing it with other herbs and dyes and exporting it at massively inflated profit margins. Their complex money laundering scheme, however, attracted the attention of the authorities.

In a statement, Europol said they had identified more than 500 shipments of the product, worth an estimated €10 million.

Age-old problem

Such schemes will come as no surprise to those working in this space, where herbs and spices fraud has been rife for many years. One study, from 2017, found that almost 90% of tested oregano samples contained at least one bulking agent – and the mean level of adulteration was a staggering 50%.

As a general rule of thumb, the more processed a food is, the more vulnerable it is to fraud. Herbs and spices, then, are intrinsically vulnerable to adulteration and are among the top five commodity groups prone to fraud. It usually involves “bulking up” shipments with similar looking plant materials, or the addition of unapproved dyes.

Oregano is commonly replaced with olive, sumac, or strawberry leaves, and dried chillies and paprika often contain rice flour, bran, or even sawdust and brick powder. Ground black pepper is frequently mixed with cheaper, similar looking papaya seeds.

Herb and spice fraud is not only dishonest, it can compromise safety. In the mid-1990s , for example, fraudsters added lead oxide to paprika in a bid to improve its colour, poisoning a number of consumers. In the United States in 2017, a recall was issued for ground cumin that was found to contain lead chromate.

Pandemic exacerbation

Food fraud is a problem that has only got more difficult to manage in recent months. The Covid-19 pandemic has interrupted global supply chains and forced producers to work with new, unproven suppliers.

At the same time, infection control measures have pushed inspection online. While the Global Food Safety Initiative (GFSI) has recommended a “blended” approach to audits that include both virtual and onsite checks, certification programmes such as BRCGS and FSSC22000 are accepting fully remote food safety audits.

With less downstream support, the burden of testing falls at the raw material or final product intake stage, and so falls upon manufacturers and retailers. Because for companies who unwittingly put their names on adulterated products, the potential damage is huge.

A Harris Poll of more than 2,000 US adults in 2014 found that 55% of people would switch brands temporarily following a product recall. Fifteen per cent said they would never buy the recalled product again, and 21% said they would avoid anything from that manufacturer in future.

Product recalls are also incredibly expensive in terms of the direct costs of assembling a crisis team, removing the product from market, investigating and addressing the cause, and managing the PR. Indirect costs, such as a decline in stock, legal fees, a loss of sales, and brand damage, also contribute to the overall impact.

In fact, more than two thirds, 67%, of respondents to a survey carried out by manufacturing infrastructure company Westgate said the recall of a key food product would cost more than £30,000.

Next generation testing

Robust food authenticity testing, as mandated by both BRC and IFS, can help retailers and manufacturers of all stripes ensure their products are what they say they are.

Traditional methods, however, have an inbuilt weakness – they are targeted to detect and quantify a known substance, meaning laboratories will only find adulteration if it is in the form they are looking for. Yet it is likely that we have found but a fraction of the possible herbs and spices adulterants.

A PCR test can tell scientists if their black pepper contains papaya seeds, for example, but it can’t give a full breakdown of all plant species contained in the sample. Simply, organisations do not know – and cannot test for – what they do not know.

But non-targeted, next generation sequencing (NGS) is different. Rather than returning a simple positive/negative result, it reliably detects and reports multi-species DNA in even the most complex of samples, including herbs and spices by comparing the DNA found in a sample against an extensive database containing sequences for many thousands of species.

It allows food processing laboratories to screen for thousands of species in one test – and get same-day results.

Making change

NGS is relatively new technology, only recently making the jump from academia to the commercial setting, but the sector recognises its potential to provide real change.

The AOAC food fraud task force, for example, is working on standard method performance requirements (SMPR) for its use in testing the authenticity of a range of vulnerable food products, including herbs and spices. Others include milk, honey, and extra virgin olive oil.

Food control authorities are also taking notice, with governmental working groups in the USA and Europe alike looking at the use of non-targeted methods.

As we move forward, then, it appears that NGS will become the method of choice in food control, thanks to the pure breath of knowledge it can add to the process. Organisations that opt to stay with traditional, non-targeted approaches risk getting left behind.