Table 3.

Chi-square test comparing convergence/divergence syntheses among food groups.

Group	Description	fx2	fx1	fx3	fx2+fx1+fx3
Fruits	Observed frequency	115.00	74.00	40.00	229
	Expected frequency	95.93	66.04	66.04	229
	Adjusted Residue	3.17	1.26	−4.71
Vegetables	Observed frequency	104.00	93.00	116.00	313
	Expected frequency	131.69	90.66	90.66	313
	Adjusted Residue	−4.38	0.40	4.37
Others	Observed frequency	56.00	24.00	34.00	114
	Expected frequency	48.38	33.31	33.31	114
	Adjusted Residue	1.79	−2.11	0.16

Test	Value	df	Sig*
Qui-square	31.91	4	0.000
Phi	0.221		0.000
N of valid cases	656

Note: *Chi-square test at the significance level of p < 0.001.

We can assess the significance between the observed values comprising the data extracted from scientific studies and the expected values for each category. Residual values between −1.96 and 1.96 (−1.96 ≤ Adjusted residuals ≤1.96) do not indicate a significant difference between the expected and observed frequency. Thus, we observed a significant difference in the ‘fruits’ and ‘vegetables’ group for the fx3 and fx2 syntheses and in the ‘others’ group for the fx1 syntheses. For example, the group of vegetables has a lower tendency to show divergence (fx3) than convergence (fx2) in the value of the nutritional and residual parameters when comparing organic and conventional foods.