Assessing the interaction between drying and addition of maltodextrin to Kakadu plum powder samples by two dimensional and near infrared spectroscopy

The effect of drying (oven and freeze-drying) and the addition of maltodextrin as a carrier to Kakadu plum (Terminalia ferdinandiana) puree powder samples were evaluated using a combination of two dimensional (2DCOS) and near infrared (NIR) spectroscopy. Fruit powder samples were obtained from an experiment where oven and freeze-drying methods were compared together with the addition of seven levels of maltodextrin to the samples (control, 5, 7.5, 10, 15, 20 and 25% w/w). Samples were scanned using a FT-NIR instrument (Tango, Bruker, Germany) and data analysed using 2DCOS. Asynchronous and synchronous 2DCOS spectroscopy were used to analyse and interpret the effects of the method of drying and the addition of maltodextrin on the NIR spectra of the fruit samples. The utilization of 2DCOS combined with NIR spectroscopy showed how the drying method affect the NIR spectra and thus the main implications of developing an effective, quick, and easy to use protocol for determining the drying method.

Temperature and Maturity Stages Affect Anthocyanin Development and Phenolic and Sugar Content of Purple-Pericarp Supersweet Sweetcorn during Storage

Purple-pericarp sweetcorn (PPS) is a novel product, requiring both purple pigment development and maintenance of sweetness. Storage period and temperature had a profound impact on total anthocyanin accumulation (TAC) and sugar content. While TAC remained relatively unchanged during 14-day storage at 4 °C, the first recorded observation of continuing accumulation of anthocyanin and phenolic compounds was concurrent with an increase in purple pigment coverage across the surface of the kernel at 23 °C. TAC in PPS significantly increased, doubling after 14 days at 23 °C. Anthocyanin concentration and kernel coverage were also affected by harvest maturity. The results indicated that biosynthesis of anthocyanins is still occurring during postharvest storage of PPS. A significant decline in sugar concentration was also observed during storage with a greater decline at 23 °C. As anthocyanin accumulation and maintaining sweetness are important factors for sweetcorn, identifying storage temperatures that optimize both quality criteria are required.

Comparison of Phenolic Compounds, Carotenoids, Amino Acid Composition, In Vitro Antioxidant and Anti-Diabetic Activities in the Leaves of Seven Cowpea (Vigna unguiculata) Cultivars

Cowpea is a well-known nutrition rich African leafy vegetable that has potential to sustain food and nutrition insecurity in sub-Saharan Africa. Consumption of cowpea legumes is associated with reduced risk of type 2 diabetes mellitus. Therefore, the present study was designed to evaluate the (i) variation in phenolic metabolites in seven cowpea cultivars (VOP1, VOP2, VOP3, VOP4, VOP5, VOP7, and VOP8 using UHPLC coupled with high resolution Q-TOF-MS technique, (ii) in vitro antioxidant activity using ferric reducing/antioxidant capacity (FRAP) assay (iii) in vitro anti-diabetic effects and (iv) composition of carotenoids and amino acids of theses cowpea cultivars. The results of this study demonstrated that gentisic acid 5-O-glucoside, quercetin 3-(2G-xylosylrutinoside) and Quercetin 3-glucosyl-(1->2)-galactoside were highest in VOP1 VOP4 and VOP5, respectively. High inhibition (>50%) of α-glucosidase and α-amylase activities was shown by the leaf extracts (50 and 25 mg/mL) of VOP1 and VOP4. Cowpea cultivars VOP1 and VOP4 demonstrated the highest gene expression levels of regulation of glucose transporter GLUT4 in C2C12 skeletal muscle cells, similar to insulin. A positive correlation exited between the phenolic components and the inhibitory effect of antidiabetic enzymes and FRAP activity. Cytotoxic effect was not detected in vitro in any cowpea cultivar. Lutein (124.6 mg/100 g) and all-trans-beta-carotene (92.6 mg/100 g) levels were highest in VOP2 and VOP1, respectively. Cowpea cultivars VOP3 and VOP4 showed potential to fulfil the daily requirements of essential amino acids. Thus, based on this information, cowpea (leaves) genotypes/cultivars can be selected and propagated for the further development of supplementary foods or functional food ingredients.

Purified plant cell walls with adsorbed polyphenols alter porcine faecal bacterial communities during in vitro fermentation

A simplified in vitro model to indicate microbiota changes to polyphenols associated with dietary fibre in whole fruits, noting differences in bacterial populations between polyphenolic groups during fermentation.