Fruit leathers are dehydrated fruit products which are eaten as snacks or desserts. They are flexible sheets that have a concentrated fruit flavor and nutritional aspects. Most fruit leathers are prepared by mixing fruit puree and other additives like sugar, pectin, acid, glucose syrup, color, and potassium metabisulphite and then dehydrating them under specific conditions. Various drying systems including combined convective and far-infrared drying, hot air drying, microwave drying, solar drying, and sun drying have been used to make fruit leathers. Most fruit leathers are dried at 30 to 80°C for up to 24 hours until the target final moisture content (12–20%) has been reached. Research about fruit leathers began in the 1970s. This work has reviewed published papers on fruit leathers in order to summarize useful information about fruit leathers on methods of preparation, effects of drying condition, and effects of packaging and storage, which will be useful to many in the food industry and consumers who are health-conscious.

A study was conducted to determine the effects of different levels of apple juice concentrate (AJC), blackcurrant concentrate (BCC) and pectin on the moisture content, water activity, color, texture and ascorbic acid content of apple-blackcurrant fruit leather using the response surface methodology. The results showed the moisture content increased with increasing pectin level and with greater increases at higher AJC and BCC levels while the water activity increased with increasing pectin level and with increasing AJC level, at low pectin levels, but with decreasing AJC, at high pectin levels. The chroma decreased with increasing pectin level and with lower values at the middle AJC level. The puncturing force decreased with increasing AJC level but with a lower value at the middle pectin level. Lastly, the ascorbic acid content increased with increasing BCC level regardless of AJC and pectin levels. There is a need to reduce the drying temperature or time of apple-blackcurrant fruit leather just enough to bring the water activity closer to 0.60, thereby increasing the moisture content resulting in higher product yield.

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Ulluco (Ullucus tuberosus Loz) is an Andean crop that has recently been reintroduced into New Zealand. Nutritional analysis and sensory evaluation were undertaken using standard methods. Ulluco contained high carbohydrate and ®bre levels, moderate protein and low fat. Panellists were asked to assess the overall acceptability of raw and cooked ulluco and to state their preferences for colour, bitterness, sweetness and mealiness of cooked ulluco. Red was the most preferred skin and tissue colour of ulluco over plain yellow and mixtures of yellow, green and red. There were no signi®cant differences in panellists' preferences for taste between ulluco cultivars, although panellists disliked the appearance of the multicoloured cultivars. The successful cultivation of this crop in New Zealand in the future will depend on optimising growing conditions and educating consumers about the aesthetic appeal of the different skin and tissue colours.