Long- and short-range structural characteristics of pea starch modified by autoclaving, α-amylolysis, and pullulanase debranching

Adaptive innovation of green plants by horizontal gene transfer

Horizontal gene transfer (HGT) refers to the movement of genetic material between distinct species by means other than sexual reproduction. HGT has contributed tremendously to the genome plasticity and adaptive evolution of prokaryotes and certain unicellular eukaryotes. The evolution of green plants from chlorophyte algae to angiosperms and from water to land represents a process of adaptation to diverse environments, which has been facilitated by acquisition of genetic material from other organisms. In this article, we review the occurrence of HGT in major lineages of green plants, including chlorophyte and charophyte green algae, bryophytes, lycophytes, ferns, and seed plants. In addition, we discuss the significance of horizontally acquired genes in the adaptive innovations of green plants and their potential applications to crop breeding and improvement.

Dual modification of various starches: Synthesis, properties and applications

The problems associated with native starches (NSs) and single modified starches were stated in order to justify dual modification of various starches. Broadly, there are two types of dual modification, i.e., homogeneous dual modification and heterogeneous dual modification. The combination of two physical modifications, e.g., (extrusion/annealing); two chemical modifications, e.g., (succinylation/cross-linking) and two enzymes modification (α-amylase/pullulanase) falls under the former classification and the latter classification is the combination of two of each of the differently stated modifications, e.g., acetylation/annealing, extrusion/succinylation, and microwave-assisted phosphorylation, etc. The classification, synthesis, properties and applications of dually modified starches were discussed. There is an attempt to elucidate the problems of each of the single modification in order to justify dual modifications. In dual modifications, the order of reactions, the reaction conditions, the medium of reaction, and the botanical sources of the various starches are very important parameters.

Effect of repeated heat-moisture treatments on the structural characteristics of nanocrystals from waxy maize starch

The effect of repeated heat-moisture treatment (RHMT) on the structural characteristics of waxy maize starch nanocrystals was investigated. Compared with native waxy maize starch (WMS), waxy maize starch nanocrystals (WMSNs) changed the crystalline pattern from A-type to B-type, and displayed the lower crystallinity (RC), molecular order (MO), enthalpy (∆H) and double-helix (DH) content, indicating a reduction in the long- and short-range orders of starch molecules. Single heat-moisture treatment significantly increased values, including RC, MO, α (power law exponent obtained by SAXS), ∆H, DH, and the melting temperatures (To, Tp and Tc), while repeated heat-moisture treatment further increased values of these parameters except ∆H, indicating the reinforcement of the long- and short-range orders of WMSNs. In addition, repeated heat-moisture treatment also caused a gradual conversion from B-type to "A + B"-type (Cb, Cc to Ca polymorphs in sequence) and finally to A-type crystallites.

The retrogradation characteristics of pullulanase debranched field pea starch: Effects of storage time and temperature

The structural changes and retrogradation behavior of the processed pea starch stored at 4 °C and 25 °C for different length of time (6, 12, 24, 48, and 72 h) was investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), solid-state 13C nuclear magnetic resonance spectroscopy (13CNMR), Fourier transform infrared spectroscopy (FT-IR), and small angle X-ray scattering (SAXS), their corresponded physicochemical properties were studied by rapid visco-analyzer (RVA). A mixture of B- and V-type crystalline polymorph was observed by XRD for all processed and retrograded pea starch. A continuous increase in the following parameters was observed during the initial retrogradation of pea starch for 6-48 h at 4 °C and for 6-24 h at 25 °C, followed by a decreased trend during the subsequent storage time from 48 h to 72 h at 4 °C, and from 24 h to 72 h at 25 °C, including the values of relative crystallinity, degree of order, and degree of double helix measured by XRD, 13CNMR, and FT-IR, respectively. The results of this study would provide useful information for better designing of starch-based food ingredients with improved functional and health benefits.