Christian Hilaire, French stone fruit researcher, is working to define stone fruit taste indicators for retail use to help consumers.

Christian Hilaire, French stone fruit researcher, is working to define stone fruit taste indicators for retail use to help consumers.

Scientists at the Balandran research station in southeastern France are studying stone fruit eating qualities and consumer satisfaction to help growers and retailers deliver a more desirable product.

"Eating quality is very complex," said Christian Hilaire, stone fruit researcher at the Balandran Technical Institute Center for Fruits and Vegetables. "Eating quality combines several factors, including sugar, aroma, acidity, juiciness, and firmness, but not all the factors are controllable." Growers can’t control the weather, which can impact eating quality attributes, but they can influence eating quality through horticultural practices. Some eating qualities are linked to specific varieties.

"A bad variety can never be good, but a good variety can be bad depending on management practices like crop load, thinning, harvesting at optimum dates, and such," Hilaire said.

CTIFL researchers are using both trained tasting panels and untrained consumer panels to help them identify consumer preferences of eating quality attributes. Trained panels involve 15 tasters; consumer panels involve 100 people. Panelists sample half a piece of fruit, and the other half is analyzed in a laboratory. Fruit are stored at 20°C (68°F) at 80 percent humidity for two to three days before sampling is conducted.

Hilaire said that with today’s availability of white-fleshed and subacid yellow-fleshed peach and nectarine varieties, defining consumer preference is more difficult than before. "But the wide range of varieties is good for the consumer because it provides for more diverse tastes."

Quality indicators

They are working to define quality indicators that can be used to group and promote varieties by taste, such as sweet, semi-sweet, low acidity, etc. Consumers know what to expect with apple varieties, he said, noting that consumers know a Granny Smith apple is more tart than a Gala. "But with stone fruit, the consumer never knows what variety he or she is buying, and it will likely be a different variety the next time the consumer goes in to buy fruit."

Some parameters of quality indicators are easy to measure, like those that can be analyzed in a lab. Others involving sensory analyses are more difficult.

For example, he said it has been difficult to determine the ideal sugar-to-acid ratio because of diverse consumer preferences. However, their research has shown that for very low or very high acid varieties, higher Brix of at least 10 percent sugar is needed to please the same number of consumers as a cultivar with a balance of sugar and acid would.