Sainsbury's is claiming two UK firsts in fresh produce by marketing tamarillos and kumquats-on-the-vine to UK consumers, as it continues to expand its exotics offer.

Many shoppers will not have come across tamarillos in the past. Also known as the tree tomato, they are normally deep red in colour, although Sainsbury's is claiming a UK first with its offer of yellow-gold New Zealand product.

Smooth-skinned and shaped like an elongated plum, the fruit is the same colour as they are externally but darker towards the middle. Sliced, they form the same pattern as a tomato but the depth of colour makes them very attractive for decorating a dish.

Fruit buyer Dominique Schulenburg feels the fruit's usp is its aesthetics.

'The combi-pack of gold and red that was launched last week is visually very strong and sales show an excellent customer reception,' she says.

Meanwhile, kumquats-on-the-vine will be going into store on June 18.

'This is another first,' says Schulenburg. 'It seems crazy no-one has ever done it before really, given the popularity of tomatoes-on-the-vine.' She concedes the reasons for this is probably because kumquats are generally not bought for their eating qualities.

'They have a very sharp citrus flavour that isn't much different to orange rind,' she says. 'They're lovely sliced into drinks, frozen into ice cubes and cooked into jams or chutneys but not to everyone's taste to munch on their own.' Still, JS's further forays into the exotic should raise the firm's profile – if its research proves correct.

Studies commissioned by the multiple have shown the presence and range of exotic fruit is extremely important to Sainsbury's customers – who, says the survey, continue to associate the chain with exceptional range and quality.

'[It's all about] providing an inspiring and educational shopping experience,' says Schulenburg.

'This is illustrated across fresh produce with our extensive range of varieties and products but strongly demonstrated by our extensive exotic fruit range, refreshed regularly with new fruits and enticing promotions that inspire customers to try something new.' The retail giant has carried out several customer focus groups looking at exotic fruit. From these groups it discovered how important it is to educate the consumer on new products.

'A total redesign on all fresh produce packaging earlier in the year enabled us to incorporate more education on the pre-packed lines within exotic fruit, including both pictorial and written information,' says Schulenburg.

The exotic fruit variety pack sold by JS has been a breakthrough, claims Schulenburg.

'We realised the demand for customers to be able to sample new fruits – the variety pack offers customers a chance to buy a selection of fruits at the affordable price of £1.99.' The product contains lime, rambutan, tamarind, passionfruit, kumquats and physalis.

To further stimulate demand, and to overcome the consumer's unwillingness to spend money of something they do not know if they like, Sainsbury's will continue to offer free exotics samples within its stores.

'We have recently sampled Asian pears, paw paws and mangoes,' says Schulenburg.