For these series we had two rows with 15 trees each of moderate size that were thinned for this experiment in a special way to get more shaded grown fruit than normally. The picker has standardised for size very well (see fruit size). We see a correlation between less sun and later or less ripeness (more starch and less sugar, so a higher Streif index).
Realise, in all trees, also where shaded grown fruit is picked, the outer side of the tree is exposed to the sun and the leaves have been assimilating in the sun. So, only the position of the fruit in the tree is in full sun, half sun or in the shadow.
3.3.4
Series D: shelf-life
Fruit for this series is collected from series A (picking date 4) and is stored in mechanical storage for three months at 4°C and high humidity. At the end of December every 4 days part of this fruit is taken out of the storage and kept at room conditions (16°C and varying humidity). So at the second week of January we collected a series of apples with different shelf lives. D1=A4 is used as short stored reference and is already measured in October. D2, D3, D4, D5 are all stored for about 3 months and have an increased shelf-life. See table 4 for the summary. To get a series with very altered fruit, we chose a very late picking time for mechanical storage purpose. Despite this we got no bad quality like mealy tasting, soft and rot. A compliment for the orchard, but a pity for this project. After storage the fruit, with little rot spots was not tested.
4
Method
This chapter describes the working sequence, the methodological steps, experimental design, sampling method, statistics and the structure of the report.
4.1
Working sequence
In §1.1 already the risk is mentioned of reasoning in circles. We are searching for a new concept with new parameters. We cannot avoid this risk but when describing our line of thought as clear as possible we can be addressed for thinking faults and wrong assumptions. This is the only way to introduce new concepts and new parameters. So we cannot speak about a traditional proof but only check for consistency and suitability of a hypothesis in different situations and products. Here we try to do the first check on experimentally grown series of apples and refer to the methodical steps as described in Bouter/van Dongen (1995) and in Houten/Diegem (1990).
Our method and working order was:
1. We had a preliminary hypothesis about a new quality concept being more suitable for organic products, introduced in §1.1 in terms of what we consider as the basic life processes in organisms: ‘growth’, ‘differentiation’ and ‘integration’.
2. We chose 5 experimental series (ripening, bearing, light exposure, bio-dynamic preparations, ageing) because in every series we expected one or more aspects of the life processes will vary.. This is our ‘golden standard’ for the criterion-validation.
3. To make this quality hypothesis operational we selected conventional and experimental parameters that may be useful to the concept. In each chapter (§5-§17) concerning a single parameter this assumption is
explained in the subject heading ‘background’, the method is described and the results of our measurements are first discussed as facts and if relevant, compared with earlier experience in literature. After considering the correlations in §18, the headlines in the series in §19 and the life processes in §20, we discussed each parameter in relation to the series and the hypothetical concept and added this to each parameter chapter. 4. We checked the sub-sample similarity for some parameters in more than one sub-sample (for practical reasons
we had to work with different sub-samples in the different laboratories) in §18.2 and drew conclusions about the similarity.
5. We compared the parameters with each other in §18.3 for relevant correlations and costs. This helped to classify parameters in §20 and check the several domains on internal consistency. After a number of similar projects we can choose the most promising and least costly parameters for quality control.
6. We summarised the results of the parameters in each series separately as facts and next arose a whole image around the changing factor(s) per series in §19. First we compared this with our expectation based on the results of the conventional parameters and next checked the consistency and expectation of the results of the experimental parameters.
7. We did this the other way around in §20 and summarised the three life processes in relation to the different parameters to double check on consistency of the traditional parameters and to find the relationship between the experimental parameters based on correlations in §18 (face-validity).
8. We checked the suitability of the concept in discussions with fruit growers and consumers and this lead to the double and connected lines in the vital quality concept (first steps according to content-validity). One aspect of suitability is the communication with growers in terms of processes they are used to managing in their fruit growing practice (growth, differentiation and integration). The other aspect of suitability is the
communication with the consumer about properties of the product, making clear that a vital quality apple differs from a ‘bag of water with nutrients and flavours’. We found the quality concept sufficient suitable to present in this report, but are still searching to find a better proof for the process of integration. More details are discussed in the following chapters.
4.2
Experimental design, sampling and analyses
We had no independent repetitions of treatments in the orchard. We collected one sample of 120 apples from 10 to 20 trees per treatment and divided it into equal sub-samples judged by eye. To reduce natural variation we standardised as much as possible (fruit size, bearing, exposure to the sun, medium or high position in the tree). Because we work with series we get certainty from a consequent line in the successive treatments instead of the independent repetitions.
A project with many partners at different places in the Netherlands and Germany has the disadvantage of working with different sub-samples on different dates and long transport. The costs of analyses do not permit as many repetitions as we wished.
The apples mature slowly in the fridge (4-6° C) and faster outside. When we compare the samples of different analyses we must realise this influence.
See table 5 for which parameters share the same sub-sample and for the out-of-the-fridge-period of the samples. All measurements and judgements are done with blind samples. This is especially important for the parameters where a subjective part is included as in crystallisation and Bovis.
4.3
Statistical analyses
The statistical analyses were performed with the statistical package SPSS version 8 (Norušis 1998).