What’s the difference between fresh versus frozen fruits and vegetables? In this article we share how our frozen ‘ulu compares to fresh products, using science to explain three key differences in harvesting, processing and storage.
Note that when frozen raw, the fruit has an unpleasant “sappy” flavor when thawed. However, fully ripe raw fruit freezes well. Frozen breadfruit should be defrosted in the refrigerator. After thawing, lightly steaming it before use will restore the original texture.
The quality of frozen foods once they are thawed depends on the rate at which they are frozen. It is important to cool through the range of temperature of minus 0.5°C to minus 5.5°C as quickly as possible since this causes least damage to the food structure. To achieve this, blast freezers are used as they blow very cold air across the food at very high speed; commercial processing operations use large scale blast freezers. These freezers are very expensive and the cost can only be justified if there is a sufficient supply of breadfruit available, or other complementary products, to enable the freezers to operate for eight hours per day for five days a week.
Chilling/cooling only slows deterioration – it does not stop it. Therefore chilling is a procedure used to maintain fruit quality when there is a delay in delivering freshly harvested fruit to the customer. In recent work in Samoa, postharvest experiments have shown that the maximum storage life for the variety puou was 11 days and 16 days for ma’afala fruit based on 17°C cool storage. The only equipment needed for chilling is a large refrigerator.
The significant advantage that breadfruit flour has over other starch-based commodities is gelling properties. It disperses almost instantly in cold water and does not clump. It is a perfect gluten-free base of instant soups and sauces and is a direct gluten-free replacer for corn flour (Fig. 11). Breadfruit flour therefore has enormous potential as a gluten-free thickener in products such as blancmange, gravy thickener and instant pudding (Fig. 12), but this level of value-adding is still mostly in the research stage.
Traditional sun drying is a long process and problematic in countries where there is consistently high humidity. A successful alternative is simply to use cooked, mashed breadfruit that can be added to dough. Successful bread has been made from two-thirds flour dough with one-third breadfruit mash. This sidesteps the need to dry the breadfruit into a powder.
Freezing is an expensive process and it is important to remove inedible portions of the fruit. Hence before freezing, ripe breadfruits are washed, peeled and cut into convenient sections (often decided by the pack size or the market specifications) with any seeds removed. The breadfruit must be delivered to the processor in the best possible condition; any delays will see a breakdown in the breadfruit texture. The washed, peeled and cut breadfruit is then packaged and frozen (Figure 3). It is important to package frozen food in (at least) 50 micron polypropylene (your supplier will help). Packaging choice depends on the shelf expected shelf life of the product. If two days shelf life is required (say for the local school or a fete) then polythene will do. For up to 6-8 weeks 50 microns thickness of polypropylene is required. For shelf life beyond 8 weeks five component composite is required (as exemplified by the commercial crisp and snack food market). Foods dry out in the freezer and also some flavours can migrate from one food to another causing ‘taint.’ Domestic home freezers are suitable for small scale processing. Chest freezers are preferred because less ambient/warm air enters the freezer as they are opened and closed.
Steaming + Freezing Locks in Nutrients
Before freezing our breadfruit, we parcook the fruit by steaming it. Steaming deactivates the enzymes in ‘ulu which would otherwise digest important antioxidants and nutrients as the fresh fruit ages. Low storage temperature further slows down the breakdown of nutrients in food, and that is why we quickly freeze our ‘ulu after steaming to lock in nutrients.
Storing & Freezing Breadfruit | Food & Tunes
FAQ
How do you preserve raw breadfruit?
Is raw breadfruit safe to eat?
Can breadfruit be frozen?
The breadfruit must be delivered to the processor in the best possible condition; any delays will see a breakdown in the breadfruit texture. The washed, peeled and cut breadfruit is then packaged and frozen (Figure 3). It is important to package frozen food in (at least) 50 micron polypropylene (your supplier will help).
Can you freeze walnuts?
Yes, you can, to keep the crispiness, place them in an airtight bag, with the least amount of air possible, and take it to the freezer for up to 6 months. You can also separate individual portions into several bags and defrost gradually. To defrost, the ideal is to defrost, put it in a shape and take it to the preheated oven at 100ºC for about 15 / 20 minutes.
Can you freeze ripe breadfruit?
Freezing is an expensive process and it is important to remove inedible portions of the fruit. Hence before freezing, ripe breadfruits are washed, peeled and cut into convenient sections (often decided by the pack size or the market specifications) with any seeds removed.
Should breadfruit be refreezed after thawing?
Instructions on labels must include ‘Store at minus 18°C’ and ’Do not refreeze after thawing.’ A large surface area is important for drying so slicing the breadfruit is the first step in the drying process; this enables the water to be removed through the surface more efficiently.