HUMAN PRACTICES

Introduction

The freshness and safety of food is a topic of growing concerns. Our product design uses a biological spray that is directly sprayed on the food’s surface to prevent and kill pathogenic organisms. A safe food sterilizer that can come in direct contact with food and enter the human digestive is still rare on the market and maybe eye-opening for the average family. Therefore, it becomes critical and our key objective to understand the necessity of the product, case scenarios of end-user, consumer acceptance, and safe design. We adjust our product design through constant communication with residents, enterprises, and experts.

Our HP work consists of four major sections: laws and regulations, social research, interviews with catering companies, and interviews with experts.

Laws and Regulations

Before our team started brainstorming, we were conducting the necessary basic reference reading, including readings that related to synthetic biology, review-type academic papers, Chinese food industry standards, laws and regulations, etc.

The reference of synthetic biology monographs and academic papers partly come from CNKI database, Google Scholar, and from the recommendations of coaches and researchers in these related fields.

The Chinese food industry standards, laws and regulations documents come from our search on government websites. Besides, while we were in the process of doing HP, some relevant catering companies were also very enthusiastic in providing us with relevant legal documents and training documents for their staff. These documents gave us a direct understanding of the current stage of fresh food disinfection requirements in the catering industry, and also allowed us to locate the needs of society from them and provide inspiration for our project.

（1）State Council Health Administration Department Website
GB29921-2021 “National Standard for Food Safety Limits of Pathogenic Bacteria in Prepackaged Foods”
GB2762-2022 “Limit of Contaminants in Food”
GB19295-2011 “Instant Frozen Noodle and Rice Products”

（2） Enterprise Sharing
GB31654-2021 “Food Safety National Standard General Hygienic Practice for Food Service”
“Sanitary Code for Defrosting Frozen Raw Materials”
“Rules for the Operation Process of Backroom Departments of Haidilao Catering Co.”
“Product Quality Management Measures for Stores”
“Product loading management standard requirements”
“Freshly cut beef and mutton receiving, storage and distribution standards”
“Measures for the Management of Unqualified Products of Supply Chain Ingredients and Supplies”

According to the pathogenic bacteria and their pathogenic risk, the International Committee for Food Microbiological Standards classifies S. aureuus as a general hazard pathogenic bacteria and adopts a three-level sampling scheme. The specific meaning of the three-level sampling scheme is: the number of products sampled from the same batch (n), the limit value of the acceptable level of microbiological indicators (m), the maximum number of samples allowed to exceed the value of m (c), and the maximum safe limit value of microbiological indicators (M).

According to this standard, we have compiled eight categories of food with the limit of S. aureuus.

Social research

Kitchen is important channel connecting fresh food and dinning table. Food does not used may return to kitchen. Therefore, understanding people's food safety awareness and daily kitchen cleaning procedures may help us accurately targeting user needs and product functions. Also, it may help us understand the market's attitude towards biological products. We completed questionnaires for 28 restaurants and collected 152 questionnaires for the general public through online questionnaires.

Through the survey of the general public and restaurants, we found the necessity and market feasibility of our project. At the same time we demonstrate in the experiment and improve the safety of products has become an important project throughout our work.

Important results of public research 1. The public cares about pathogenic microorganisms in food, but does not know much about them
2. The public thinks that food contamination by pathogenic microorganisms can be judged by using their senses. However, the existence of food contamination is difficult to be detected by people's senses.
3. Refrigerators are the only method that most families can use to keep food safe overnight.
4. More than half of people are willing to try biologic cleaners that apply directly to food surfaces, but more than a third still have doubts.

(2) Important research results of catering kitchen:
1. Most of the workers from stores and shops investigated also care about the pathogenic microorganisms in the food, but they do not know much about the pathogenic microorganisms, and they also judge whether the food is safe to eat by their senses just like the general public.
2. Discarding and refrigeration are the main disposal methods for unused fresh food in food and beverage stores.
3. In the investigated food and beverage stores, washing is a way to disinfect and clean fresh materials in the store.
4. Human safety is the most important standard for biological cleaning products from the sellers.

Companies interview

Catering enterprises and food companies have strict hygiene standards and killing processes. There is also a realistic demand for clean and fresh food products. Therefore, we visit a top 500 catering chain stores and a dairy enterprises, and have one-to-one conversation with the person responsible of charge aiming at product safety problem where the interviewed public pay a lot of attention.

Haidilao Hotpot

Hotpot, also known as Chinese Fondue, is one of most popular meals in China and requires a high standard on food hygiene. Serving raw foods on the table ready to be cooked as part of the set up, the catering companies want to ensure the dishes look fresh on the outside and, more importantly, safe at the microbial level. Therefore we visited and surveyed two hot pot stores of different chain brands.

We had the honor to interview with the manager Mr.Si of one of the most representative restaurants - Haidilao. This restaurant was founded in 1994 and has since become China’s largest chain of hot pot restaurants. Our interview was light-hearted but informative. We spoke about the impact of the pandemic on the industry, food management and classification, customer’s concerns of using spray products, and their advice.

The manager explained his store’s measures for food safety in 3 categories: hygienic storage of fresh and frozen foods, hygienic handling, and hygienic environment in the store.

We got some important reflections as follows:
(1) Catering stores are very cautious about disinfection products (both for tableware and food itself) as health and safety are more significant than the effects of it.
(2) Under the conservative attitude of disinfection products, in order to ensure the cleanliness of fresh food, discarding has became the main way to guarantee such cleanliness, which caused a lot of operating costs and food waste.
(3) Catering stores, like the general public, have doubts about biological products about whether they will have adverse effects on human health after long-term use.

We also described our project design to the Si manager, who gave us some enlightening advice regarding the security description:
(1) The public may not know much about professional scientific knowledge, and it is better to explain the safety of materials (proteins, engineered bacteria, etc.) used in the product
(2) We should explain whether there will be mistakes in the work of our biological products, resulting in poor effects or adverse effects on human body.
In response to these two recommendations, we improved and emphasized them in the Safety section of the project. Because we understand that our projects have to be accountable to the public and businesses.

Brightdairy company

We are honored to be able to interview Ms. Yang the manager from the quality management department of Brightdairy company. The company has a history of hundreds of years dating from 1911. It has maintained the position of pioneer dairy company in China for many years and had applied for a plentiful patent in the field of the dairy product.

We designed our interview to be rather simple. First, we asked about the effect of the pandemic and the sustained overheating in Chengdu. The answer was that it did not affect the procedure of production but did add extracurricular to their employee. We then asked about the sterilization process during production. We received the information that the company utilizes heating and automatic cleaning for its products and equipment. We then asked about the transportation and packaging. The manager stated that they use a temperature monitor and GPS to observe the condition of their product. In addition, they employed Tetra Pak to avoid direct sunlight and to isolate the product from the airborne microorganism. At last, we inquired about the value or possibility of employment of our product. The manager maintains that if the price could be less than the current product they are using and would maintain the quality and safety of their product, they would be willing to try the product showing that the market is willing to employ our product.

This information allowed our team to have more background knowledge of dairy companies, and using this knowledge, we can determine the process in which our product can be involved.
（1）Our main focus could be on the dairy itself. Since our product will allow the company to shorten the time wasted in the sterilization process of dairy.
（2）Moreover, our product can also be involved in the cleaning process of equipment. As S. aureus may be present on anything water-related, our product would enhance the sterilization of equipment.
（3）Our products can also be involved in the transportation of fresh milk ensuring the daily safety of the outer packaging of fresh milk and yogurt delivered. Daily delivery of dairy products is sealed in recyclable glass bottle containers by using simple tin foil which requires more secure outer packaging.

We are also reminded that the value of our product is dependent on the potential risk, cost, and effectiveness. Neglecting the cost and effectiveness that can be calculated after experiments, our team still need to consider what negative effect could be present in our product and how can we solve them with current techniques.

*We have planed an interview with Bright dairy company, but the pandemic rushed in and interrupted our plan for the past few month. Therefore, we only have pictures for our online interview with Bright-dairy company.

Expert interview

The two-way communication with experts in related fields provided useful suggestions for the 3 stages of our design, enabling us to think about the rationality, safety and public acceptance of the design from more aspects.

Gastroenterologist(Stage 1)

Dr. Ma
Dr. Ma is a gastroenterologist at the Fourth People's Hospital of Sichuan Province. Through interviews, we learned that clinical cases of Staphylococcus aureus(S. aureuus) are common, and most infections are caused by unclean diet. It is easy to multiply in milk and meat, and easy to grow in leftover food. It produces enterotoxin after 6-12 hours of reproduction at 37℃. This toxin has strong resistance to heat, and can still cause disease after boiling for 30 minutes.

The results accord with our conjecture in brainstorming, we further recognize the value of our work. At the same time, Dr Ma reminds us to consider whether the product will filter out bacterial that has drug resistance. Also, we have to consider whether the product will kill bacteria are beneficial to human body which may leads to the flora disorder of human body.

Dietitian(Stage 1)

Dr. Feng
Dr. Feng, a dietitian at the Fourth People's Hospital of Sichuan Province, does not recommend to eat overnight meals because, there are potential contamination risks, and the nutritional value of the food itself is compromised. We also showed Dr. Feng the vision and initial design of our project, and she said that biological products directly used in food should consider the following aspects:
1. It should not cause any health hazard to human body
2. Food spoilage should not be covered up
3. Quality defects in the food itself or in its processing should not be covered up
4. The nutritional value of food itself should not be reduced

Product quality inspection experts(Stage 2)

Dr.Yue Xiang
Dr.Yue Xiang is the technical director of Product Quality Supervision and Inspection Institute of Jilin Province. In the online video conference with her, she introduced to us the standards, processes and methods of quality testing in the food industry from the perspective of policies, regulations and industry standards. In the laboratory operation link that we were interested in, she explained to us the sampling and testing standards of meat products, dairy products and other fresh food in the laboratory, and things need to pay extra attention on such as"people, machines, materials, methods and rings" in laboratory testing. People: Personnel with professional operation skills; Machine: The machine works properly; Material: the experimental reagent is effective; Method: The detection method should meet the international standard; The ring experiment environment meets the requirements of fresh food testing. These shares have improved our understanding of laboratory operations.

Researchers in the field of synthetic biology(Stage 2、3)

Dr. Jiequn Wu
Dr. Wu, a researcher at Zhejiang University of Technology, has in-depth research on biological quorum sensing. He affirmed our courage in incorporating protein-labeling technology into the project, and reminded us that if our goal is to inhibit the production of toxin by quorum sensing in S. aureus, we need to prove it through experimental design.

Dr. Hailong Gao
Dr. Gao, who is currently at Harvard Medical School, mentioned us to pay attention to protein specificity problems of AgrD: whether the protein in the design will cause off-target effects with the homologous origin of the protein in the human body. This is something we did not think of before, so we studied this problem through a literature search, and finally found that AgrD is specific that it does not cause off-targeting. We also added this part into design description to improve the security of the project.

Dr.Jialing Wang
Dr.Wang at Rockefeller University, suggested that we should think about whether we should design protein purification experiments for our project. After discussion, we added histone tags to the design process to facilitate the purification proteins later and enable proteins to be labeled more efficiently.