BACKGROUND: Perah seed is one of the most underutilized oilseeds, containing high nutritional values and high percentage of α-linoleneic acid, which may have a high potential in food and pharmaceutical applica- tions. The main objective of this study was to evaluate the influence of microwave (MW) cooking on the proximate composition and antioxidant activity of perah seeds.
METHODS: In this study, the proximate composition and amygdalin concentration of MW ir- radiated perah seeds were determined. The total phenolic content (TPC), Maillard reaction products (MRPs) and antioxidant activity of methanol (PME), 70% methanol in water (PMW), ethanol (PEE), 70% ethanol in water (PEW) extracts and methanol extract of oil (PMO) were evaluated during MW cooking. The anti- oxidant activity was evaluated using multiple assays, namely DPPH radical scavenging activity, β-Carotene bleaching assay, and reducing power.
RESULTS: Microwave cooking did not significantly increase crude lipid and carbohydrate content, and the amounts of other nutrients such as ash, crude protein and fibre remained almost unchanged. As evaluated by HPLC, the amygdalin concentration in the seeds was reduced by MW cooking. The TPC, MRP and anti- oxidant activity of the solvent extracts of perah seeds increased significantly with increasing roasting time. Of all the extracts, PMW at all MW cooking times displayed the highest antioxidant effectiveness. However, thermal treatment significantly reduced the antioxidant properties of PMO. The values for TPC, MRP and antioxidant effectiveness of the samples were ranked in the following order: PMW > PEW > PME > PEE > PMO, in both control and microwaved samples.
CONCLUSIONS: In determining the overall quality of the products, MW cooking time was found to be a critical factor. Solubilization of phenolic compounds and formation of MRPs during MW cooking could have caused the increase in antioxidant activity of the perah seeds.
The availability of data produced from various sequencing platforms offer the possibility to answer complex questions in plant research. However, drawbacks can arise when there are gaps in the information generated, and complementary platforms are essential to obtain more comprehensive data sets relating to specific biological process, such as responses to environmental perturbations in plant systems. The investigation of transcriptional regulation raises different challenges, particularly in associating differentially expressed transcription factors with their downstream responsive genes. In this paper, we discuss the integration of transcriptional factor studies through RNA sequencing (RNA-seq) and Chromatin Immunoprecipitation sequencing (ChIP-seq). We show how the data from ChIP-seq can strengthen information generated from RNA-seq in elucidating gene regulatory mechanisms. In particular, we discuss how integration of ChIP-seq and RNA-seq data can help to unravel transcriptional regulatory networks. This review discusses recent advances in methods for studying transcriptional regulation using these two methods. It also provides guidelines for making choices in selecting specific protocols in RNA-seq pipelines for genome-wide analysis to achieve more detailed characterization of specific transcription regulatory pathways via ChIP-seq.
The impact of microwave roasting on the thermooxidative degradation of perah seed oil (PSO) was evaluated during heating at a frying temperature (170°C). The roasting resulted significantly lower increment of the values of oxidative indices such as free acidity, peroxide value, p-anisidine, total oxidation (TOTOX), specific extinctions and thiobarbituric acid in oils during heating. The colour L* (lightness) value dropped gradually as the heating time increased up to 12 h, whereas a*(redness) and b* (yellowness) tended to increase. The viscosity and total polar compound in roasted PSO was lower as compared to that in unroasted one at each heating times. The tocol retention was also high in roasted samples throughout the heating period. The relative contents of polyunsaturated fatty acids (PUFAs) were decreased to 94.42% and saturated fatty acids (SFAs) were increased to 110.20% in unroasted sample, after 12 h of heating. On the other hand, in 3 min roasted samples, the relative contents of PUFAs were decreased to 98.08% and of SFAs were increased to 103.41% after 12 h of heating. Outcome from analyses showed that microwave roasting reduced the oxidative deteriorations of PSO during heating.