1. Conclusion and perspectives
STUDY OF THE AGING AND THE SHELF-LIFE EXTENSION OF FRUIT FILLINGS CONTAINED IN BUCKETS
de Caritat H., Delacharlerie S., Sindic M., Deconinck T.  Gembloux Agro-Bio Tech, Université de Liège (ULg), Unifine Food and Bake Ingredients
Summary: The management of logistic and stock matters encourages the pastry industry to develop quality products with a long shelf-life. This study is based on the desire of Unifine Food and Bake Ingredients to increase the shelf-life of its fruit fillings. Different fruit fillings (apples, cherries, strawberries) have first been selected. The aging of the products was then characterized through physico-chemical and sensory analyses. Browning and the loss of hardness of the fruits have been identified as the major alterations of the studied products. After searching for the causes of these alterations, it turned out that the heat treatment applied to the studied fruit fillings is sufficient to destroy the enzymes responsible for browning. However, this heat treatment also leads to a decrease in ascorbic acid content, which can promote browning. Finally, several ways of improvements were tested. It seems that an increase in ascorbic acid content and / or an addition of calcium ascorbate may contribute to a slight slowdown of the involved alterations.
Characterization of fruit fillings
Identification of the origins
of the apple filling alterations
Possible improvements tested
Conclusion and perspectives
The results enable us to propose some improvements and advice :
For a better understanding of the mechanisms of the browning of apple fillings, it would be appropriate to analyze the presence of o-quinones. These molecules are truly the cornerstone of enzymatic browning.
The texture of apples also degrades through some enzymatic reactions. Therefore, it would be interesting to examine more deeply the possibility of using the thermo-sonication.
Finally, it could be interesting to determine the shelf-life of actual product, although this was not the subject of the initial request Unifine. This has unfortunately not been undertaken. To do this, a larger number of samples would have been necessary to have a more regular serie of products. A sensory analysis using a panel of consumers would have assessed the shelf-life.
Fruit filling alterations
Result (2) : Sensory analyses
Title
Introduction
Methods
Results
Discussion
Conclusion
References
Result (1) : Presence of polyphenol oxidase
Result (1) : Ascorbic acid substitution
Title
Introduction
Methods
Results
Discussion
Conclusion
References D
An addition of ascorbic acid or calcium ascorbate have positive effets on the browning.
Many causes can conduct to the deterioration of the fruit fillings. From the arrival of the fruits to the manufacturing processes and the storage conditions. Practically, different mecanisms could appear :
enzymatic browning;
non enzymatic browning (coupling reactions, ascorbic acid oxidation, Maillard reaction, …);
texture changes (viscosity, consistency, hardness,…);
taste and odor changes.
Odor (intensity)
Sweetness
Salty taste
Bitter taste
Aroma
Viscosity
Acidity
Color (intensity)
Apple pieces and syrup,
untreated and treated with a Gaiacol solution
Cut pieces, untreated and
untreated with a Gaiacol solution
Reference
3 months
11 months
25 months
Apple filling
Odor (intensity)
Sweetness
Salty taste
Bitter taste
Aroma
Viscosity
Acidity
Color (intensity)
Apple pieces before and after the
dipping bath, untreated and treated
with a Gaiacol solution
Result (2) : Ascorbic acid degradation
Analysis of variance for erythorbic acid addition
The differences between days of measures are very highly significant. But no relevant changes were observed by the ascorbic acid substitution.
Approach
Result (2) : Correction of the ascorbic acid content
Aging
(1,2,3,4)
Apple (P)
Physico-chimical analysis (Colorimetry, Brix degre, pH, Consistance, Baking stability, Aw, Texture)
Intralot variability (a,b,c)
Interlot variabilité (P,P',P")
Sensory analysis
Odor (intensity)
Sweetness
Salty taste
Bitter taste
Aroma
Viscosity
Acidity
Color (intensity)
Reference
5 months
8 months
Cherry filling
Months
Syrup color
Fruit color
Aroma (intensity)
Salty taste
Odor (intensity)
Acidity
Sweetness
Bitter taste
sity
Fruit hardness
Aroma (type)
Ascorbic acid losses during the aging of the apple filling
Conclusion (1) & (2) : Heat treatment sufficient for enzyme destruction but leads to ascorbic acid destruction
Result (3) : Puree homogeneity
0 days
Incubator at 37°C during 18 days
Colorimetric parameters of the tested formulations
The apple puree appears inhomogeneous. Several factors could explain these color and density differences. The sample collect, the manufacturing process or the raw materials. A further standardization is desiable to avoid variations.
Result (1) : Softening of apple pieces
Odor (intensity)
References
Salty taste
Color (intensity)
Reference
7 months
Strawberry filling
Result (3) : Addition of calcium ascorbate
Texture : Penetration needle (2mm)
Hardness (g)
Les polyphénols en agroalimentaire. Sarni-Manchado P., Cheynier V., Eds.; Lavoisier : Paris.
Technologies de transformation des fruits. Albagnac G., Varoquaux P. et Montigaud J.-C., Eds.; Lavoisier: Paris.
Science des aliments. Jeantet R., Croguennec T., Schuck P., Brulé G., Eds.; Lavoisier: Paris.
Bitter taste
Viscosity
Result (4) : Apple hardness
Apple filling
Syrup color
Fruit color
Aroma (intensity)
Odor (intensity)
Acidity
Bitter taste
osity
Fruit hardness
Sweetness
Aroma
Salty taste
Acidity
Sweetness
Statistical resullts of the hardness of apple pieces with calcium ascorbate addition
Hardness comparison between fresh and processed apples
Contact : Hervé de Caritat
Age (months)
A too short incubator duration (18 days at 37°C) don’t allow us to distinct a significant maintaining of the apple hardness.
No obvious correlation in hardness has been found on these products.
The hardness decreased from nearly 200g to less than 90 g in 11 months time.
Aroma (type)