Plum-Good Improvements

Dried-plum fiber. Prune skins leftover from making prune juice are dried and ground to a powder. What is left is a highly hygroscopic, mostly insoluble fiber, rich in macro- and micronutrients and low in fat and sugar. Since it is only partially digestible, it contains only 1.5 calories per gram.

Dried-plum oil. The fibrous outer coating of the prune pit is removed and the inner kernel is extruded and expeller-pressed. The oil smells like sweet almonds and has a rich, golden hue. It has a high smoke point (460°F) and is 94% mono- and polyunsaturated fat.

Dried-plum purée. Whole pitted prunes are cooked and concentrated in an evaporator before mixing with prune paste (whole, sieved prunes). The resulting product is fat- and cholesterol-free, yet quite viscous, and functions effectively as a fat replacer. It is high in vitamin A, natural sugars and sorbitol. Since it is only partially digestible, it contains only 2.5 calories per gram.

In addition to these three, two other, more-established dried-plum ingredients were available for us to work with: plum concentrate (a viscous 70° Brix prune-juice concentrate) and dried-plum pieces (diced, dried plums, 22% moisture).

Sunsweet defined four common bakery products for us to perform applications research on that they felt would represent the potential of its ingredients: muffins, brownies, cookies and bread. For us, these products would provide insight into multiple leavening systems, specifically yeast, chemical agents and aeration. While it was immediately apparent that each ingredient had different functional characteristics, our task was to develop a body of detailed applications knowledge. We needed to understand each product’s benefits, as well as its limitations.

Even before benchtop work commenced, it was clear the prune fiber would take up water, which meant an adjustment in the percentage of water in each bakery formula would be necessary. This could be viewed as a benefit (water is cheap), and the trapped water would also help keep the products moist and fresh longer. The fiber would provide some flavor, but we also found it was gritty and would darken a light-colored product.