Balsamin, a novel ribosome-inactivating protein from the seeds of Balsam apple Momordica balsamina

Plant seeds, a rich source of proteins, are considered important for their application as functional ingredients in a food system. A novel ribosome-inactivating protein (RIP), balsamin was purified from the seeds of Balsam apple, Momordica balsamina. Balsamin was purified by ion exchange chromatography on CM Sepharose and gel filtration on superdex-75. It has a molecular weight of 28 kDa as shown by SDS-PAGE analysis. Balsamin inhibits protein synthesis in a rabbit reticulocyte lysate-based cell free translation assay with an IC50 of 90.6 ng ml⁻¹. It has RNA N-glycosidase activity and releases a 400-base long fragment termed the Endo fragment from 28S rRNA in the same manner as does saporin-6 from Saponaria officinalis. The N-terminal sequence analysis of the first 12 amino acids of balsamin revealed that it shares 83% similarity with type I RIP α-MMC from Momordica charantia and 50% similarity with β-MMC (from Momordica charantia), bryodin I (from Bryonia dioica) and luffin a (from Luffa cylindrica). Balsamin was further characterized by mass spectrometry. CD spectroscopic studies indicate that secondary structure of balsamin contains helix (23.5%), β-strand (24.6%), turn (20%) and random coil (31.9%). Thus RIPs activity expressed in vegetables like Momordica sp. advocates its usage in diet.

Sowing the seeds of farmer health

 This book contains a series of chapters developed from presentations made at the 2012 NCFH Conference ‘Sowing the Seeds of Farmer Health’. Each of the chapters helps fulfil the NCFH’s ongoing vision of “inspiring quality education, research and service delivery through innovative partnerships that advance agrihealth locally and globally”. This book provides an opportunity to document and distribute the lessons and innovative approaches developed in the field of agricultural health, wellbeing and safety, and provides a sound basis for ongoing work into the future.

Long-distance endozoochorous dispersal of submerged macrophyte seeds by migratory waterbirds in northern Europe - a critical review of possibilities and limitations

We review whether migratory Anatidae, i.e., swans, geese and ducks, could be acting as vectors for dispersal of Zostera, Ruppia and Potamogeton propagules by endozoochory (carrying seeds in their guts). We list six prerequisites that must all be fulfilled, if successful dispersal should occur. Several Anatidae species feed on these macrophytes, and undertake rapid long-distance movements, making dispersal possible. We identify four problems, which in combination leads us to conclude that long-distance dispersal events are likely to be rare. (i) Most long-distance movements are out of phase with the reproductive efforts of the plants, and if birds arrive at sites when plants still bear seeds, they are likely to depart well after seed stocks have been depleted. (ii) Seed transport by birds will usually be uni-directional, from north to south on autumn migrations. (iii) Most of the gut contents of migratory birds are likely to have been discarded within 300 km of departure. (iv) In many cases, birds will arrive in habitats seriously different from those they departed, i.e., any seeds carried along will have low chances of surviving in their new site. We suggest that northbound dispersal by endozoochory can only occur during spring if waterbirds feed on seeds that have not been depleted and remained frozen down or buried in sediments, or during moult- or post-moult migrations. Moult migration takes place in summer in phase with the reproductive efforts of the plants. Also epizoochorous dispersal (external attachment) is subject to restrictions i, ii and iv.

Physicochemical and functional properties of protein isolate produced from Australian chia seeds

Protein was isolated from Australian chia seeds and converted to powders using spray, freeze and vacuum drying methods, to investigate the effect of drying methods on physicochemical and functional attributes of chia-seed protein isolate (CPI). It was found that there was no significant difference in the proximate composition; however vacuum dried CPI (VDCPI) had the highest bulk density and oil absorption capacity, whereas spray dried powder (SDCPI) demonstrated the highest solubility, water absorption capacity and lowest surface hydrophobicity. Solubility of all powders was higher at elevated temperature and alkaline pH. Foaming capacity and foam stability of CPI were found to increase with increasing pH and protein concentration. SDCPI was the least denatured and VDCPI the most denatured, demonstrating the poorest solubility and foaming properties of the latter. These findings are expected to be useful in selection of a drying process to yield chia seed protein powders with more desirable functionality.