Effects of Holding Methods and Time on the Vitamin Contents of Five Tropical Leafy Vegetables

Five tropical leafy vegetables, Pterocarpus soyauxii (“oha”), Pterocarpus santalinodes (“nturukpa”), Gongronema latifolium (“utazi”), Corchorus olitorius (“ahihiara”) and Amaranthus hybridus (“green”) were held for four days at ambient condition using three different popular local methods used in the Southeastern states of Nigeria. Each leafy vegetable was divided into three lots. Lots I and II were unwrapped while lot III was wrapped with broad cocoyam leaves. The three lots were held under a shade. In addition, lot II was regularly taken outside to the open at nights where it was exposed to cool air and early morning dews. The vitamin contents of each leafy vegetable lot were analysed initially and on daily basis for four days. The beta carotene and ascorbic acid contents ranged respectively from 4.88 – 9.84ìg and 105.62 – 278.65 mg per l00 g of the leafy vegetable. The five leafy vegetables are fair sources of thiamin, riboflavin and niacin. There were losses in the vitamins as holding time increased, regardless of the holding method employed. The rate of loss of vitamins was highest in Lot I (the unwrapped leaves that were kept in a shade both day and night). The rate of loss of vitamins was lowest in Lot III (the wrapped leafy vegetables).Keywords: Leafy vegetables, vitamins, method, time, loss

The Quality Properties Of Tomatoes (Lycopersicon esculentum) As Influenced By Processing With A Chemical Preservative And Storage

Blanched sulphited and unblanched unsulphited tomato slices (control) were subjected to different storage temperatures (6-8oC) and (-12oC) respectively for 15 weeks. Solar dried (blanched sulphited and unblanched unsulphited) tomato slices were stored at ambient temperature (28-30oC). Within the 15 weeks of storage, ascorbic acid,pH, titratable acidity, microbial population and sensory attributes were determined Blanched sulphited frozen (BLSF), unblanched unsulphited frozen (UNUF), blanched sulphited solar dried (BLSSD) and unblanched unsulphited solar dried (UNUSD) samples showed a decrease in pH with an increase in titratable acidity during storage. On the other hand blanched sulphited refrigerated (BLSR) and unblanched unsulphited refrigerated (UNUR) samples had an increase in pH and a decrease in titratable acidity. The moisture content of both frozen and solar dried samples reduced but that of refrigerated samples increased. The frozen samples retained more ascorbic acid (69.26% for BLSF and 55.41% for UNUF) than other samples but the blanched sulphited frozen sample retained the highest ascorbic acid (69.26%). The solar dried samples were better (45% for BLSSD and 48.15% for UNUSD) than the refrigerated samples which retained lesser ascorbic acid (30.57% for BLSR and 26.55% for UNUR). The frozen and solar dried samples showed an appreciable decrease of microbial population while there was an increase in the refrigerated samples at the end 15 weeks. Sensory evaluation indicated no significant differences in colour, flavour, texture and general acceptability between the blanched sulphited frozen and the fresh tomatoes at P< 0.05. Blanched sulphited solar dried and unblanched unsulphited solar dried samples were inferior in color, texture and general acceptability but not in flavour. Key words: Blanching, sulphiting, Solar drying, Tomatoes. Nigerian Food Journal Vol.22 2004: 195-20

In Vivo Dopamine Neuron Imaging-Based Small Molecule Screen Identifies Novel Neuroprotective Compounds and Targets.

Parkinson's disease (PD) is the second most common neurodegenerative disorder with prominent dopamine (DA) neuron degeneration. PD affects millions of people worldwide, but currently available therapies are limited to temporary relief of symptoms. As an effort to discover disease-modifying therapeutics, we have conducted a screen of 1,403 bioactive small molecule compounds using an in vivo whole organism screening assay in transgenic larval zebrafish. The transgenic model expresses the bacterial enzyme nitroreductase (NTR) driven by the tyrosine hydroxylase (th) promotor. NTR converts the commonly used antibiotic pro-drug metronidazole (MTZ) to the toxic nitroso radical form to induce DA neuronal loss. 57 compounds were identified with a brain health score (BHS) that was significantly improved compared to the MTZ treatment alone after FDR adjustment (padj&lt;0.05). Independently, we curated the high throughput screening (HTS) data by annotating each compound with pharmaceutical classification, known mechanism of action, indication, IC50, and target. Using the Reactome database, we performed pathway analysis, which uncovered previously unknown pathways in addition to validating previously known pathways associated with PD. Non-topology-based pathway analysis of the screening data further identified apoptosis, estrogen hormone, dipeptidyl-peptidase 4, and opioid receptor Mu1 to be potentially significant pathways and targets involved in neuroprotection. A total of 12 compounds were examined with a secondary assay that imaged DA neurons before and after compound treatment. The z'-factor of this secondary assay was determined to be 0.58, suggesting it is an excellent assay for screening. Etodolac, nepafenac, aloperine, protionamide, and olmesartan showed significant neuroprotection and was also validated by blinded manual DA neuronal counting. To determine whether these compounds are broadly relevant for neuroprotection, we tested them on a conduritol-b-epoxide (CBE)-induced Gaucher disease (GD) model, in which the activity of glucocerebrosidase (GBA), a commonly known genetic risk factor for PD, was inhibited. Aloperine, olmesartan, and nepafenac showed significant protection of DA neurons in this assay. Together, this work, which combines high content whole organism in vivo imaging-based screen and bioinformatic pathway analysis of the screening dataset, delineates a previously uncharted approach for identifying hit-to-lead candidates and for implicating previously unknown pathways and targets involved in DA neuron protection