Summary

• ​The Administrative Regulation No. 13/2016 “Maximum Limits of Mycotoxins in Food" has been promulgated and is in force in Macao. It regulates and establishes the maximum limits of mycotoxins in specific types of food products;
• It is difficult for the human eye to detect the initial growth of mould and mycelia, and the presence of mycotoxins in fruits. As such, when members of the food industry found that any fruit or vegetable has suffered mechanical damage, is overripe, or moulded, they should discard the whole fruit or vegetable;
• The sector should inspect fruits and vegetables for any unusual conditions rendering them unfit for sale or consumption in a timely manner, and discard the affected ones. Such conditions include surface damage, presence of dark spots, moulds, mycelia, or dents, localised softening, depressed area, deformation, souring, or giving off an alcoholic smell;
• Use fresh fruits and vegetables to prepare fruit and vegetable juices and fruit and vegetable-based products (e.g. mango sago, and fruit and veggie cups);
• It is advisable to buy fruits and vegetables in small quantities over several times to ensure their freshness. If the food placed around a mouldy fruit or vegetable is contaminated by mould, discard it promptly to avoid cross-contamination.

Introduction

       The spoilage and moulding of fruits and vegetables are typical quality issues in food supply chains. Yet, from a food safety perspective, the associated risks extend far beyond mere deterioration of organoleptic properties of fruits and vegetables. Moulds are capable of producing mycotoxins (e.g. patulin) which are heat-resistant, unobservable, and cumulative in effect during the spoilage process of fruits and vegetables. The ingestion of a small amount of mycotoxins can have adverse effect on human health.

       In the past, the Municipal Affairs Bureau (IAM) issued food alerts due to possible contamination of pre-packaged fruit juice beverages by patulin, and instructed the food sector to recall and remove the affected products from shelves. As to ensure food safety, the sector's knowledge on the microbial changes and mechanism behind mycotoxin formation during the spoilage process of fruits and vegetables is crucial to establishing effective control of food safety. This article integrates scientific knowledge with local laws and regulations to provide the food sector with a systematic analysis and some practical advice.

Microbial changes in fruits and vegetables from ripening to senescence

         The natural wax layer covering the surface of fruits and vegetables helps to prevent the penetration of microorganisms, so their internal tissues are typically bacteria-free or with minimal presence of microorganisms. However, when this outermost layer of fruits and vegetables is damaged by insect bites or mechanical damage (e.g. bruising or freezing), or that the fruits and vegetables become overly ripe and their intercellular adhesion weakened, microorganisms can penetrate through the wounds on them and multiply, accelerating the spoilage process.

     The physiological characteristics of fruits and vegetables (such as pH value and water activity) determine their susceptibility to certain microbial groups. The primary microorganisms of concern that cause spoilage of fruits and vegetables are moulds, yeasts, and a few bacterial species. When provided with favourable conditions, moulds gradually become the dominant fungal genera.

        Moulds reproduce by means of tiny spores that are invisible to the naked eye, which spread through air and water, or during food-handling. When spores encounter favorable conditions (such as wounds on the surface of fruits and vegetables, and over-ripe fruits and vegetables), moulds begin to multiply in the wounds or on spots on the surface where contaminants are attached. It is only when moulds have proliferated to a significant level and formed large colonies that they are observable with the naked eye. It is particularly important to note that some genera of moulds produce water-soluble mycotoxins (e.g. patulin) during their multiplication, which can diffuse into the seemingly normal pulp of the fruit through tissue fluids. Even if the mouldy parts are removed, there is still a risk of ingesting mycotoxins.

        Fruits or vegetables with fresh bruises should be consumed as soon as possible to prevent the growth of microorganisms. However, in practice, the food sector cannot determine the time when the fruits or vegetables get bruised. As to ensure fruits and vegetables are safe for consumption, whenever members of the food sector find out that any fruits or vegetables have suffered mechanical damage, are overripe, moulded, or show signs of abnormality, they should discard the whole fruit or vegetable.

Regulatory aspects in Macao

        According to Law No. 5/2013 “Food Safety Law" in effect in Macao, the food sector has the responsibility to ensure the food products supplied or served are in good hygienic conditions and are safe and fit for human consumption. Moreover, all commercially available food products, as well as their raw materials, must comply with the series of promulgated food safety standards that are in effect.

        The Administrative Regulation No. 13/2016 “Maximum Limits of Mycotoxins in Food" has been promulgated and is in force in Macao. It regulates and establishes the maximum limits of mycotoxins in specific types of food products.

       Moreover, IAM has been monitoring the safety of food products commercially available in the market through routine food surveillance, inspection of seasonal and festive food products, targeted food surveillance and a food incident monitoring system. It will take immediate actions to contain the spread of food safety risks according to their intensity and extent. It will also disseminate information about the situation in a timely manner for the information of the public and the food sector, so as to ensure food safety in Macao.

Advice to businesses of fruits, vegetables, and fruit and vegetable-based products

Purchase with caution

• ​Prioritise suppliers with GAP (Good Agricultural Practices) certification to ensure that mechanical damage to fruits and vegetables is minimised during their harvesting and transportation;
• Purchase the quantities based on the estimated sales volume.

Proper storage

• Store different types of fruits and vegetables at the appropriate temperatures and humidity to slow down their ripening and inhibit microbial growth;
• Avoid excessive compression of fruits and vegetables to reduce chances of mechanical damage;
  
• Store fruits and vegetables by type and according to their degree of ripeness;
• Follow the “first ripened, first out" rule in storage and use of fruits and vegetables and shorten their storage time as far as practicable.

Timely inspection

• ​Check on fruits and vegetables in a timely manner, for any unusual conditions rendering them unfit for sale or consumption, and discard the affected ones. Such conditions include surface damage, presence of dark spots, moulds, mycelia, or dents, localised softening, depressed area, deformation, souring, or giving off an alcoholic smell;
• Discard the whole fruit or vegetable even if it shows the above-mentioned conditions in a specific area;
• If the food placed around a mouldy fruit or vegetable is contaminated by mould, discard it promptly to avoid cross-contamination;
• Use fresh fruits and vegetables to prepare fruit and vegetable juices, and fruit and vegetable-based products (e.g. mango sago, and fruit and veggie cups).

Comprehensive training

• Heighten food handlers' awareness of risks posed by spoiled fruits and vegetables to avoid the misuse of mouldy raw materials due to cost considerations.

Advice to the public

• Buy fruits and vegetables in small quantities over several times to ensure their freshness;
• Store fruits and vegetables at the appropriate temperatures. For example, refrigerate high-moisture fruits (e.g. strawberries and grapes) and consume them as soon as possible. Store tropical fruits (e.g. mangoes and bananas) at room temperature;
• Before consumption of any fruits or vegetables, check for surface damage, presence of dark spots, moulds, mycelia, or dents, localised softening, depressed area, deformation, souring, or giving off an alcoholic smell. Discard ones that show signs of abnormality at once;
• Do not consume or use mouldy fruits and vegetables. Discard the whole fruit or vegetable even if it is partially mouldy;
• If the food placed around a mouldy fruit or vegetable is contaminated by mould, discard it promptly.

BRR 002 DAR 2025