Effect of genotype in the production and quality of sweet sorghum juice [Sorghum bicolor (L.) Moench]

Abstract

Objectives: To evaluate the production of juice and sugar, the physicochemical parameters of the juice during extraction and quantify the differences between genotypes.
 Design/Methodology/Approach: An experiment under irrigation was established with 10 genotypes of sweet sorghum in southern Sonora, México, during the autumn-winter cycle, under a randomized block complete design with four replicates. The sowing dates were 03/15/2015 and 02/20/2016. The variables were: days to flowering (DF), weight of fresh biomass (T ha-1): whole plant (WTo), stem (WSt), leaf (WLf), and panicle (WP). After extraction, juice weight (WJ), bagasse weight (WBz), juice volume (JV), and extraction efficiency (EFx:WJ/WSt) were determined. The juice was sieved to remove impurities. There were determinate at the time of extraction: pH, temperature (°C) and degrees Brix.
 Results: The sources of variation had a significant effect on the production of biomass, juice, and sugar. The year contributed to explain 53 % of the variation, the genotype explained 36 %, while the interaction (GxA) only 5 %. On average, the production of fresh stem biomass was 38 t ha-1, with 28 % efficiency in juice extraction. The SWS686 and SWS694 genotypes exceeded the average in juice production and the control (M81E). Juice production in 2016 was higher (31 %) than in 2015. In average, the juice values were of 32 °C, 12.9 oBrix and pH 3.8.
 Study/Limitations/Implications: The decrease in the content of soluble solids and spontaneous fermentation during the conservation of the juice under room temperature can limit the use of sweet sorghum in areas where temperatures are >30 °C in post-harvest stage.
 Findings/Conclusions:There was an effect of the environment and genotype on the production and quality of sweet sorghum juice. It is necessary to make a complete analysis of the life cycle that indicates the challenges and opportunities to improve the efficiency of the processes to obtain sweet sorghum juice