ABSTRACT
BACKGROUND: Knowledge of the variation of extractable protein amount in legumes and grasses as affected by harvest time is important for identifying optimal combinations to enable a high protein production in a biorefinery. The extractability of protein was estimated using the Cornell Net Carbohydrate and Protein System across six harvests during the spring growth. RESULTS: The estimated extractable protein [g kg-1 dry matter (DM)] defined as the easily available fractions B1 +B2 was significantly higher in white clover and lucerne at all harvests while, if the more cell wall attached fraction B3 can be extracted, white clover had the highest extractable protein amongst all species. Total yield of B1 +B2 per ha was higher in white clover and red clover at the early growth while B1 +B2 +B3 was by far the highest for red clover through all harvests. CONCLUSION: White clover could be a good candidate for protein production purpose in a biorefinery due to its high extractable protein content per kg DM. In order to maximise the protein production capacity, harvest should take place during early growth due to a decline in protein extractability with maturity. The final economy of the concept will depend on the value of the fibre after extraction of the protein. © 2017 Society of Chemical Industry.
Subject(s)
Animal Feed/analysis , Fabaceae/chemistry , Plant Proteins/chemistry , Poaceae/chemistry , Animals , Fabaceae/growth & development , Plant Proteins/isolation & purification , Plant Proteins/metabolism , Poaceae/growth & development , Poaceae/metabolism , Rumen/metabolism , Seasons , Silage/analysisABSTRACT
Effect of supercritical CO2 extracted Nigella sativa L. seed extract (NE) on frying performance of sunflower oil and refined, bleached and deodorized (RBD) palm olein was investigated at concentrations of 1.2 % and 1.0 % respectively. Two frying systems containing 0 % N. sativa L. extract (Control) and 0.02 % butylated hydroxytoluene (BHT) were used for comparison. Physicochemical properties such as fatty acid composition (FAC), Peroxide Value (PV), Anisidine Value (AV), Totox Value (TV), Total Polar Content (TPC), C18:2/C16:0 ratio and viscosity of frying oils were determined during five consecutive days of frying. Results have shown that N. sativa L. extract was able to improve the oxidative stability of both frying oils during the frying process compared to control. The stabilizing effect of antioxidants were in the order of BHT > NE. RBD palm olein was found to be more stable than sunflower oil based on the ratio of linoleic acid (C18:2) to palmitic acid (C16:0) and fatty acid composition.
ABSTRACT
The aim of this study was to optimize the antioxidant activity of Piper nigrum L. essential oil extracted using the supercritical carbon dioxide (SC-CO2) technique. Response surface methodology was applied using a three-factor central composite design to evaluate the effects of three independent extraction variables: pressure of 15-30 MPa, temperature of 40-50 °C and dynamic extraction time of 40-80 min. The DPPH radical scavenging method was used to evaluate the antioxidant activity of the extracts. The results showed that the best antioxidant activity was achieved at 30 MPa, 40 °C and 40 min. The extracts were analyzed by GC-FID and GC-MS. The main components extracted using SC-CO2 extraction in optimum conditions were ß-caryophyllene (25.38 ± 0.62%), limonene (15.64 ± 0.15%), sabinene (13.63 ± 0.21%), 3-carene (9.34 ± 0.04%), ß-pinene (7.27 ± 0.05%), and α-pinene (4.25 ± 0.06%). The essential oil obtained through this technique was compared with the essential oil obtained using hydro-distillation. For the essential oil obtained by hydro-distillation, the most abundant compounds were ß-caryophyllene (18.64 ± 0.84%), limonene (14.95 ± 0.13%), sabinene (13.19 ± 0.17%), 3-carene (8.56 ± 0.11%), ß-pinene (9.71 ± 0.12%), and α-pinene (7.96 ± 0.14%). Radical scavenging activity of the extracts obtained by SC-CO2 and hydro-distillation showed an EC50 of 103.28 and 316.27 µg mL(-1) respectively.
