Development of ultra-high performance liquid chromatographic and fluorescent method for the analysis of insect chitin
FOOD CHEMISTRY
Authors: Han, Xiaocui; Heinonen, Marina
Abstract
A precise quantification of insect chitin is needed in order to avoid overestimation of crude protein due to chitin-bound nitrogen. An UPLC/FLR method was optimized and validated for the determination of glucosamine (GlcN) hydrolyzed from chitin in insect materials. The method was applied for quantifying the chitin content in mealworms (Tenebrio molitor) and crickets (Acheta domesticus). A baseline separation was obtained using an Acquity HSS T3 C18 column, with an external calibration curve of excellent linearity, and a low limit of de-tection and quantification of GlcN. Even though the recovery of GlcN from spiked cricket material was slightly lower compared to that using spectrophotometric method, the UPLC/FLR method proved a sensitive and specific method of quantification of insect chitin. Chitin contents in T. molitor and A. domesticus were 4.6 +/- 0.1% and 4.5 +/- 0.0% on dry matter basis, respectively. Less than 0.01% of chitin was present in insect protein-enriched fractions extracted with 0.1 N NaCl at pH 10.
Saline-water irrigation and plant growth regulator application on zucchini fruit yield and quality
REVISTA BRASILEIRA DE ENGENHARIA AGRICOLA E AMBIENTAL
Authors: Souza, Maria W. de L.; Torres, Salvador B.; de Oliveira, Francisco de A.; Marques, Isabelly C. da S.; Pereira, Kleane T. O.; Guimaraes, Itala T.
Abstract
The objective of this study was to evaluate the effect of a plant growth regulator (PGR; Stimulate') on the yield and quality of zucchini fruits from plants of the cultivar Caserta-Italiana grown under different salinity levels of the irrigation water (SLIW). A randomized block design was used, in a 2 x 6 factorial arrangement consisted of two SLIW (0.5 and 5.0 dS m(-1)) and six PGR application modes: imbibition of seeds for 8 h in distilled water (PGR-T1 ; Control); imbibition of seeds for 8 h in PGR at 10 mL L-1 (PGR-T2); imbibition of seeds for 8 h in PGR at 10 mL L-1 plus foliar application at 10 mL L-1 at the flowering stage (PGR-T3); imbibition of seeds for 8 h in PGR at 10 mL IP plus two foliar applications at the flowering stage and at 20 and 30 days after sowing (PGR-T4); foliar application at 10 mL L-1 at the flowering stage (PGR-T5); and two foliar applications at 10 mL L-1 at 20 and 30 days after sowing (PGR-T6). The SLIW affected differently the variables of the zucchini crops evaluated. The PGR application to plants under no salt stress (0.5 dS m(-1)) increased the solid soluble concentration and biomass accumulation of zucchini fruits. The PGR application as seed treatment and foliar application at the flowering stage increased the fruit yield of zucchini plants irrigated with saline water.