Tempoyak
Tempoyak is a fruit appetiser developed from fermented durian pulp. Microaerophillic conditions are essential for the process while anaerobic conditions result in spoilage of the product. A 1% salt solution is added to improve the fermentation. The fermentation takes about one week during which the pH of the fermenting product drops from about 6.8 to 4.2. Tempoyak can be stored at 5ºC in bottles or plastic cups for 2 months. Changes in colour, growth of film yeasts and hardening of the surface, together with aroma and flavour changes are indications of spoilage.

Tempoyak – a delicious fruit appetizer

Lempuk
Lempuk is a traditional shelf-stable, ready-to-eat durian product classified as an intermediate moisture food (IMF), i.e. a product with characteristics intermediate between highly stable conventional dehydrated foods and highly perishable fresh foods. Its characteristics depend to a large extent on its moisture content and/or water activity.

The traditional batch production of lempuk involves mixing the durian flesh with sugar, wheat flour as a binding agent, and water, followed by heat concentration with continuous stirring of the slurry until the required consistency is attained. The hot mass is then moulded into the normally cylindrically shaped product, the length and diameter of which can be varied. The product, light to dark brown in colour, is wrapped in the traditional upih (flower sheath of coconut tree) or in suitable flexible plastic packaging films. Lempuk is a low protein, high energy food.

Others
Durian pulp can also be used to flavour other traditional products like wajik and dodol. Wajik is prepared by heating together glutinous rice, palm sugar and coconut milk to a thick consistency. Dodol is prepared by heating a mixture of glutinous rice flour, palm sugar and coconut milk.

Durian flavoured dodol

Frozen durian
Durian can be preserved and stored frozen, either as a whole fruit, as frozen fruitlets or as pulp. Preserving and freezing the whole fruit requires a lot of space, and would result in an excessively expensive product. The fruitlets, after being carefully separated, can be frozen without damage to their shape or flavour.

Durian fruitlets can also be preserved through cryogenic freezing. Liquid nitrogen at -196 °C or liquid carbon dioxide at -79 °C is used to freeze the fruitlets. The fruitlets, thawed before serving, have excellent taste, texture and colour. Alternatively, the fruitlets can be preserved through air blast freezing at -40 °C with a flow rate of 150 to 460 metres per minute until the inner fruitlet temperature reaches -18°C. The fruitlets are then stored at -18°C.

Durian pulp
After removal from the seed, it can be pulped and stored frozen for further utilisation. It can be incorporated into yoghurt to produce durian flavoured yoghurt.

Durian powder
Durian powder is produced by spray drying or drum drying the edible portion of the fruit. These methods produce durian flakes of powder with excellent qualities and can be used in the making of ice-cream and other products.

To protect the aroma, taste, texture and colour of durian powder during storage laminated aluminium foil (e.g. paper and aluminium foil and polyethylene, aluminium foil and polyethylene, cellophane and aluminium foil and polyethylene) not thinner than 0.1 mm and polypropylene film of thickness about 0.1 mm are suitable for protective retail packaging of durian powder. The shelf life of durian powder packed in bags made of laminated heat-sealable aluminium foil and polypropylene film was at least 6 months and 5 months, respectively.  

Durian leather

Fruit leather is a dehydrated sweet-sour product. It is leathery in texture, processed from fruit puree, sugar and other additives to form thin sheets of 1-2 mm thick. It can be used in baked goods, confectionery products or rolled (termed fruit rolls) and eaten as snacks.

Drying conditions affect the quality of durian leather (flavour, aroma, texture, appearance and overall acceptability). The optimum conditions for oven-dried leather are 50ºC for 12.6 hours. For cabinet-dried leather, optimum conditions were 52.5ºC for 10 h. Products dried with low temperatures-long duration were preferred over those dried with high temperatures-short duration.

Laminated aluminium foil is preferred over HDPE, LDPE and polypropylene film as a packaging material as it maintains the quality of durian leather during storage. 

Vacuum Fried Snack
Young, firm textured fruitlets can be fried under vacuum at 95-110ºC to give a crispy, less oily snack compared to that fried under conventional frying at 180-200ºC.

Confectionery Products
Confectionery products that can be produced using durian pulp are confectionery jelly, durian fudge and toffee.