WEIGHT AND VOLUME GAIN BY HYDRATED GRAINS OF BITTER ALBUS LUPINS GROWN IN CHILE

Bitter lupins ( Lupinus albus L.) produced in Araucania, southern Chile are exported to European and Arab countries and consumed as a salty snack, after a process of soaking and boiling that removes bitterness. Commercialisation of the product, generally known as ‘lupini beans’, is typically by volume, occasionally by weight, therefore weight and volume gain by hydrated seeds may affect profitability. Nine lupin lines (3 Local, 3 Italian, and 3 Moroccan) were grown in three environments. Forty plants per entry per location were randomly chosen. Twenty random single plants were threshed mechanically and 20 by hand. Five replicates used for analysis consisted each of 100 seeds obtained by sampling five random seeds per plant. Soaking time was 16 h in distilled water. Weight and volume gain means were 130% and 45%, respectively. Local and Moroccan lines gained 3% more weight than Italian lines. However, Italian lines gained 14% more volume than Moroccans and 24% more than Locals. Mechanical threshing increased weight gain by 2.8% but had no significant effect on volume gain, compared with hand-threshing. No association was found between weight and volume gain. Interestingly, volume gain was strongly linked (r = 0.86**) with dry seed weight whereas weight gain was inversely correlated (r = - 0.42**) with dry seed weight. Thus, larger seeds increased their size proportionately more than smaller seeds, even when they did not absorb more water. Small though significant differences were found among lines, even within a type. Variance component analysis (REML) estimated a significant genotypic effect, with heritabilities of 0.21 and 0.74 for weight and volume gain, respectively.