When undergoing a summer internship at Aqua Green (a local hydroponic salad company), one of our team members observed the warehouse staff carrying bags of tuna fillets from the cold rooms and dumping them into large green trash tanks - despite the fact that little to no spoilage odor was developed. The company made this seemingly unreasonable decision to ensure the quality of its final product as hot summers in Hong Kong create inevitable gaps in cold chain management.

As confirmed by Willem Landman, the company’s Technical Director, it is difficult for the Quality Control staff to conveniently and accurately determine if the fish is spoiled or safe to consume, especially since most of the inspection is performed manually, which introduces subjectivity and quality variability. This problem is worsened by the fact that some fish fillets were found to be spoiled even before the expiry date due to the aforementioned inconsistent cold chain issue.

Various discussions with Mr. Landman, who also has years of experience in corporate food quality control, suggest that a convenient and affordable testing kit to detect fish spoilage levels would help the business greatly by reducing health risks and the economic costs of discarding fish that might not have been spoiled.

Inspired by this incident, we decided to investigate this issue locally and globally by performing further research and interacting with the various stakeholders.

Local Fish Consumption

As the second largest seafood consumer per capita in Asia and the eighth globally, Hong Kong imported more than 33,000 tons of fish and produced 112,000 tons of fisheries locally in 2021^[1]. The Fish and Seafood segment is expected to continue growing by 3.05% in the next five years, generating up to 5.05 billion USD in revenue in the year 2022^[2]. Fish is no doubt an essential part of our everyday cuisine, from local wet markets to chain supermarkets to high-end hotel restaurants.

In our consumer surveys (with 40% of responses from Hong Kong consumers and the rest distributed among the U.S., Japan, Korea, and mainland China), we learned that more than 85% of respondents consume fish at least once per week, with almost 20% of them consuming more than 4 times per week, and that 30% of them mainly purchase fish from wet markets and almost 60% from the supermarket. These results indicate high consumption volume and the need for stricter fish quality control at these handling points.

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Global Fish Consumption

Looking into the global market, we observe a dramatic increase in global fish consumption from 9.0 kg per capita in 1961 to 20.3 kg in 2017 as international food trading became increasingly convenient^[3]. Despite a small decrease in the past few years, it is reasonable to assume that fish consumption level will rise back up as more countries are relaxing their Covid restrictions for imports and exports in the year 2022.

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Bioamines Level as an Indicator of Fish Quality

Produced by bacterial decarboxylation of specific amino acids as the seafood’s shelf life reaches its end, bioamines can be considered a spoilage level index. This correlation was long established by scientists more than forty years ago in the form of a biogenic amine index, as shown below.

In recent years, the scientific community continues to apply this correlation to develop devices that detect spoilage levels in different food products, including a team from Flinders University that measures bioamines levels for monitoring salmon spoilage.

Although food safety regulatory bodies in different regions have different upper limits for bioamine concentration, it is observed by many studies that consuming food with a high level of bioamines leads to intoxication like Scombrotoxin Fish Poisoning and Tyramine Toxicity^[4], potentially resulting in the following symptoms:

• Burning sensation around mouth or throat
• Rashes on the upper body
• Dizziness
• Nausea
• Vomiting
• Heart palpitation
• Respiratory difficulty

With such a high fish consumption and bioamines risks involved, its quality assurance has become an increasingly significant issue.

After performing preliminary research on fish consumption and spoilage, we shifted our focus to society & industry and arranged meetings with the various stakeholders, including local consumers & businesses, government officers, and Quality Control experts.

ConsumersBusinesses Government OfficersQuality Control Experts

The negative impacts brought by the current fish spoilage problems are three-fold: food waste, quality variability, and bioamine poisoning.

Food Waste

Fish spoilage leads to substantial food waste annually. Although local statistics are not easily accessible, it is estimated that around 20% of the total fish weight harvested globally per year was lost due to microbial contamination and spoilage. Assuming Hong Kong has a below-average loss rate of 10%, this signifies an annual loss of 14,500 tons of fish, which is enough fish for more than one million people per year according to the recommended fish intake by the Washington State Department of Health.

Even though most fish businesses in Hong Kong are reluctant to disclose the amount of fish discarded due to potential spoilage, our on-site research in Thailand suggests that up to 30% of fish parts were thrown away if unsold by the end of the day - even if the fish looks and smells normal. Businesses do this to decrease the chance of selling potentially spoiled fish to their customers. This finding confirms the substantial amount of food waste resulting from not knowing if the fish is spoiled for sure or not.

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Quality Variability

Secondly, many local fish businesses indicate that fish spoilage detection is performed manually by experienced fishermen, which introduces quality variability. According to Mr. Willem Landman, this variability amplifies throughout the supply chain and results in significant economic loss when the fish products reach the final retailers or end consumers. Mr. Henry Yip from the Hong Kong Fish Marketing Organization (FMO) also confirms the presence of this issue and emphasizes that different quality inspection standards at different handling points in the supply chain further aggravate the problem.

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Bioamines Poisoning

Lastly, although often confused with allergy, poisoning cases due to fish spoilage cannot be neglected. Just a few months ago, on June 8th, the Hong Kong Center for Food Safety reported a histamine poisoning outbreak in a local restaurant involving tuna fillets; this adds to the 26 group histamine poisoning outbreaks in Hong Kong in recent years.

Similar cases are also observed worldwide in regions like Taiwan, Japan, Korea, Sweden, Italy, Spain, and many more. According to Food Safety authorities in multiple countries, even a fish with a seemingly good appearance and no detectable odors of spoilage can contain a high level of bioamines, posing serious health threats without the presence of a convenient bioamine detector.

Despite the difficulty in estimating the number of consumers affected, it is nevertheless an important health issue to address both locally and internationally.

Upon confirming the problems, we began investigating existing or proposed solutions to see how we can develop a more comprehensive and effective product.

As described by the local seafood businesses that we interviewed, rigorous quality inspection procedures are usually performed at third-party testing laboratories, which could take up to three to five days. Although major quality inspection service providers like HQTS Group and Pro QC provide comprehensive testing reports, the interviewees explained that using external services could lead to much higher time, monetary, and logistical costs compared to an in-house testing procedure.

Food experts around the world have observed similar problems in their own communities and begun developing more convenient quality inspection methods. Take Quality Certified Foods as an example, they are “a group of scientists and food professionals that measure and quantify the quality of foods through bio-metric technology”. While their Certified Quality Reader 3.0 allows businesses to perform in-house quality inspection, it is still relatively expensive and has not been widely accepted by the general market; we suspect that their lack of public presence is due to their marketing strategy to target high-end food providers instead of the general food businesses - which are who our project targets.

Apart from fully commercialized products and services, we also looked into other research teams who are developing similar products in innovative ways. A team from the City University of Hong Kong has been working on a sensor that detects histamine and formaldehyde (the latter being an illegal additive used in seafood as preservatives but is hazardous to human health); their detection method is based on “the selective bonding interaction in vapor and liquid phase”. Having received a grant worth 20 million RMB from the Ministry of Finance, State Oceanic Administration, and Xminnov, the team aims to provide a rapid screening test that complies with the standards established by WHO and FDA.

Apart from AOAC 977.13, a widely accepted but complicated method for histamine testing, there is currently a gap in the market for a quick and user-friendly bioamines testing kit.

All these projects further convinced us of the urgency to provide a convenient method to detect food spoilage and showed us the different aspects that we can improve on top of these existing solutions.

With a comprehensive understanding of the problem, stakeholders’ opinions, and existing solutions, we decided to develop a user-friendly bioamines detection kit for smaller fish businesses. This spoilage-level testing kit is intended to be used at the retail handling point, providing all stakeholders an assurance of fish quality prior to distribution, benefiting both the fish buyers and sellers.

Upon studying the entire operational flow of a fish processing business in Hong Kong, we learned that even with proper certification and equipment for cold chain management, temperature inconsistency can still occur due to physical restriction, external environment, or human erroneous factors, leading to the need to measure fish spoilage levels at specific control points.

As such, we envision our testing kit to be incorporated into an existing framework in order to maximize the benefits it brings to the aforementioned stakeholders.

Initially developed by NASA to ensure food safety during space operations, the Hazard Analysis Critical Control Point (HACCP) system is “an effective and rational means of assuring food safety from harvest to consumption” (FDA). It is now widely implemented in the food industry and recognized as a global food quality standard. As HACCP has become compulsory for the U.S. “manufacturers of meat and poultry, seafood, and juice products” and specific food production businesses in some other developed countries, the Hong Kong regulatory body expressed their desire to follow the footsteps of international standards and further incorporate HACCP into the local food industry.^[5]

According to a research report performed by Data Bridge^[6], the global food certification market is expected to grow, indicating that more businesses in the food industry will incorporate Quality Assurance and Quality Control systems into their operations, including HACCP, which is one of the most popular and recognized frameworks. They explain that this growth is driven by the “rising consumer awareness regarding food safety, stringent food certification and standards and rising number of government initiatives to ensure food safety”.

Combining all the interviews, surveys, and studies, we believe that incorporating our testing kit in the HACCP framework would fill to current fish inspection gap and provide a more affordable alternative for smaller businesses to fulfill regulatory requirements.

[1] Agriculture, Fisheries and Conservation Department (2022, March 14). Capture Fisheries Industry of Hong Kong. The Government of the Hong Kong Special Administrative Region. Retrieved September 14, 2022, from https://www.afcd.gov.hk/english/fisheries/fish_cap/fish_cap_latest/fish_cap_latest.html

[2] Fish & Seafood - Hong Kong. (n.d.). Statista. https://www.statista.com/outlook/cmo/food/fish-seafood/hong-kong

[3] Tukker, R. (n.d.). Almost 80% of the fish consumed worldwide comes from sustainable stocks - Evidence shows that management is the best tool for conservation. Europêche. https://europeche.chil.me/post/almost-8025-of-the-fish-consumed-worldwide-comes-from-sustainable-stocks-evidenc-303635#:~:text=Global%20fish%20consumption%20rose%20from,capita%20intake%20of%20animal%20protein.

[4] Biji, K. B., Ravishankar, C. N., Venkateswarlu, R., Mohan, C. O., & Gopal, T. K. (2016). Biogenic amines in seafood: a review. Journal of food science and technology, 53(5), 2210–2218. https://doi.org/10.1007/s13197-016-2224-x

[5] Tang, S. P. (2018, April). HACCP – An Effective System to Improve Food Safety. Food Safety Focus, 117. https://www.cfs.gov.hk/english/multimedia/multimedia_pub/multimedia_pub_fsf_117_02.html

[6] Data Bridge Market Research (2021, July). Global Food Certification Market – Industry Trends and Forecast to 2028. https://www.databridgemarketresearch.com/reports/global-food-certification-market#