Quality of shelf life
September 1, 2014
by Joanie Spencer
In the past, the pre-packaged donut’s reputation for a lack of freshness meant it barely garnered more than a glance on the supermarket shelf by midday. But in recent years, donuts have experienced a renaissance of sorts, and consumers are seeing them as not only a breakfast item but also a dessert, midday snack or even a midnight treat. With donuts now getting a second look, the fresh factor is more important than ever.
The biggest challenges that frozen- and fresh-packaged donuts face are shelf life, stickiness and recrystallization of the glaze. A packaged donut should look like it was freshly packed, even after some days on the shelf or after defrosting. It should be shiny, but not sticky, with moist, tender crumb. Achieving these characteristics often depends on the glaze.
Beneo, Manheim, Germany, developed Palatinose, a functional carbohydrate that when used in combination with sucrose can lead to extended shelf life with a tender crumb, sweet taste and a transparent glaze. “A small change in formula and process can help improve the overall quality of the product and extend the shelf life,” said Katja Reichenbach, product manager, Palatinose, for Beneo.
Generically named isomaltulose, Palatinose is derived from sugar beets and produced by enzymatic rearrangement. Its molecular structure looks very similar to sucrose, and while it’s a real — albeit unique — sugar, it has a much more stable structure, Ms. Reichenbach noted.
The donut’s main challenges come mostly from the battle for moisture. “There’s going to be water migration from the layer with the highest water activity to the one with the lowest,” explained Annick Van Den Heuvel, Beneo customer technical service engineer.
Palatinose will aid in shelf life extension through its high water activity and water migration control. If it is used next to sucrose as part of the glaze composition, the water activity can be increased up to the level of the donut’s..
The ideal ratio of Palatinose to sucrose should be calculated based on the water activity of the donut, meaning that the ratio will vary depending on the formulation.
Beneo’s tests show that shelf life could extend from three to seven days, depending on the donut and glaze type, manufacturing process, packing style and formulation adjustment with Palatinose.
Moisture is also a major factor in the quality of the glaze. “The most important barometer in controlling stickiness is the water migration,” Ms. Van Den Heuvel said, noting that Palatinose has low hygroscopicity, picking up little moisture even in high humidity environments.
Palatinose has GRAS status as a nutritive sweetener in the US and is marketed by Beneo, Morris Plains, NJ. For more information on Palatinose, including an archived webinar featuring Ms. Reichenbach and Ms. Van Den Heuvel, visit www.beneo.com