The primary objectives of the present work were to produce corncob powder (CCP) from
corncobs and incorporate the CCP into bread formulation in order to develop high fibre bread,
and to investigate the physicochemical and sensory properties of the produced high fibre
bread (HFB). The corncobs were collected and washed before they underwent the grinding
and drying processes. The obtained CCP was incorporated into the bread formulation in three
different proportions (5, 10 and 20%) to partially substitute bread flour in the formulation. All
three bread samples and the control (0% CCP in the formulation) were analysed to obtain their
physicochemical and sensory properties. The incorporation of CCP significantly affected the
texture, colour and volume attributes of the produced breads. Increasing the content of CCP
in the formulation was found to be responsible for firmer, smaller and darker bread loaves as
compared to the composite bread samples. The bread formulation incorporated with 10% CCP
had the highest mean scores (7.00) of overall acceptability among all the other formulations,
and it was comparable to the commercial breads in the current market.
Separation of 1,2(2,3)- and 1,3-positional isomers of diacylglycerols (DAG) from vegetable oils by reversed-phase high-performance liquid chromatography (RP-HPLC) is investigated. The method is based on isocratic elution using 100% acetonitrile and UV detection at 205 nm. The following elution order of DAG molecular species is identified: 1,3-dilinolein < 1,2-dilinolein < 1,3-dimyristin < 1-oleoyl-3-linoleoyl-glycerol < 1,2-dimyristoyl-rac-glycerol < 1(2)-oleoyl-2(3)-linoleoyl-glycerol < 1-linolenoyl-3-stearoyl-glycerol < 1(2)-linolenoyl-2(3)-stearoyl-glycerol < 1,3-diolein < 1-palmitoyl-3-oleoyl-glycerol < 1,2-dioleoyl-sn-glycerol < 1(2)-palmitoyl-2(3)-oleoyl-glycerol < 1-linoleoyl-3-stearoyl-glycerol < 1,3-dipalmitin < 1(2)-linoleoyl-2(3)-stearoyl-glycerol < 1-oleoyl-3-stearoyl-glycerol < 1,2-dipalmitoyl-rac-glycerol < 1-palmitoyl-3-stearoyl-sn-glycerol < 1,3-distearin < 1,2-distearoyl-rac-glycerol. Linearity is observed over three orders of magnitude. Limits of detection and quantitation range 0.2-0.7 microg/mL for 1,3-dilinolein to 0.6-1.9 microg/mL for 1,2-dioleoyl-sn-glycerol, respectively. Precision and accuracy of the method are also demonstrated. The method is developed to separate mixtures of DAG molecular species produced from edible oils.
The effects of medium strategies [maintenance (M), intermediary (G), and production (P) medium] on cell growth, anthraquinone (AQ) production, hydrogen peroxide (H2O2) level, lipid peroxidation, and antioxidant vitamins in Morinda elliptica cell suspension cultures were investigated. These were compared with third-stage leaf and 1-month-old callus culture. With P medium strategy, cell growth at 49 g l(-1), intracellular AQ content at 42 mg g(-1) DW, and H2O2 level at 9 micromol g(-1) FW medium were the highest as compared to the others. However, the extent of lipid peroxidation at 40.4 nmol g(-1) FW and total carotenoids at 13.3 mg g(-1) FW for cultures in P medium were comparable to that in the leaf, which had registered sevenfold lower AQ and 2.2-fold lower H2O2 levels. Vitamin C content at 30-120 microg g(-1) FW in all culture systems was almost half the leaf content. On the other hand, vitamin E content was around 400-500 microg g(-1) FW in 7-day-old cultures from all medium strategies and reduced to 50-150 microg g(-1) FW on day 14 and 21; as compared to 60 microg g(-1) FW in callus and 200 microg g(-1) FW in the leaf. This study suggests that medium strategies and cell growth phase in cell culture could influence the competition between primary and secondary metabolism, oxidative stresses and antioxidative measures. When compared with the leaf metabolism, these activities are dynamic depending on the types and availability of antioxidants.