The analysis of strawberries as a means of determining the fruit content of manufactured products

Abstract

SummaryMultivariate statistical analysis was examined as a means of obtaining more reliable assessments of fruit contents from analytical determinations than are possible by the current use of average values of insoluble solids, nitrogen, phosphorus and potassium contents. The major portion of the investigation dealt with the fruit itself.Twenty‐three parameters were determined on fifty‐four samples of strawberries, culled during three successive seasons, and representing a wide span of cultivars, their origins and growing areas. To derive the weighting factors to be applied to the analytical determinations in order to obtain the optimum estimate of fruit content, the analytical results were submitted to multivariate statistical analysis. This approach led to a marked improvement in the estimations of fruit content when compared with conventional techniques.Wide variations were found in the levels of all of the parameters determined, but there were highly significant correlations between many pairs, in which the free amino acids figured largely. A limited study to assess the usefullness of these parameters for determining the fruit content of manufactured products showed that the amount of free amino acids recovered from fresh fruit jams and from frozen fruit were very similar. However, the amounts recovered from sulphited pulp and sulphited fruit jams did not fall into any clear pattern. Further investigation of the effect of sulphiting on the free amino acids is therefore necessary before the statistical approach can be applied in these circumstances.