Biochemical Differentiation of Cocoa Cotyledon Proteins from Various Genetic Origins

Previous studies have reported that differences in the cocoa flavour of roasted beans from various genetic origins do exist; however, the findings were mainly based on sensory evaluation. In addition, the cocoa flavours differences were also claimed to be solely due to the maternal plants and not to other factors such as physiological factors. Cocoa cotyledon contains vicilin (7S)-class globulin (VCG), a major storage protein. It is a native source of oligopeptides and free amino acids, both of which have been identified as precursors of specific-cocoa aroma. These precursors are formed by proteolysis during fermentation. The VCG and the splitting specificity of proteases from cocoa cotyledons have been known to be responsible in the production of cocoa-specific aroma precursors during fermentation. The separation patterns of VCG which were separately isolated from cocoa cotyledons of various genotypes namely Forastero, Criollo, Trinitario, PBC 140, SCA 12 and UITI are shown. Comparative studies of VCG patterns and its multiple forms were conducted by means of SDS-PAGE and two-dimensional electrophoresis (2-DIEF/SDS-PAGE), whereas oligopeptide profiles were detected using a high performance liquid chromatography. SDS-PAGE analysis of the molecular weights of the predominant polypeptides of VCG subunits (47 and 31 kDa) from various genotypes did not show qualitative differences. The 2-D IEF/SDS-PAGE analysis of the VCG subunits revealed at least 10 multiple forms with pIs in the range of 6.1 to 6.8. The additional polypeptides with their multiple forms which had pIs in the range of VCG subunits were also detected on 2-D IEF/SDS-PAGE. These polypeptides were most probably the resultant degradation proteolytic products from the action of aspartic endoprotease on VCG subunits. There were very strong similarities in the VCG subunits and their degradation products at the level of their polypeptide constituents from the standpoint of number, molecular weight and isoelectric point. The oligopeptide profiles of autolysis products of the acetone dry powder prepared from various genotypes did not revealed differences. It indicates that the action of aspartic endoprotease of the various cocoa genotypes on VCG during autolysis was similar. There was no analytical identity difference of VCG subunits and their degradation proteolytic products for all the genotypes. Thus, VCG seems not to be responsible for cocoa aroma differences in cotyledons of the various genotypes within methodical limits. The VCG was almost completely degraded as compared to the storage albumin at the end of fermentation. In conclusion, aroma differences in raw cocoa harvested from various genotypes are the result of other genotypes, physiological or curing related factors but are not due to genetic differences of aroma precursors derived from storage proteins

Lycopene content and lipophilic antioxidant capacity of by-products from Psidium guajava fruits produced during puree production industry.

The comparison of lycopene content and lipophilic antioxidant capacity was explored among pink guava fruit and by-products of its puree production industry namely refiner, siever and decanter. Lycopene content was measured using both UV–vis spectrophotometer and high performance liquid chromatography (HPLC) methods. Atmospheric pressure chemical ionization liquid chromatography–mass spectrometry (APCI-LC–MS) was applied in confirming the studied compound. Two assays were employed to determine the lipophilic antioxidant capacities namely lycopene equivalent antioxidant capacity (LEAC) and β-carotene bleaching assays. Lycopene content and antioxidant capacity were in the order of fruits > decanter > siever > refiner. Decanter exhibited the highest lycopene content and antioxidant among the studied by-products. It also gave a significant higher (p < 0.05) lycopene content than pink guava fruit based on the wet basis. There was a significant correlation between lycopene content and LEAC. All samples had a good antioxidant activity in β-carotene bleaching assay but negatively correlated to lycopene content. Decanter was found to be the highest in lycopene content (17 mg/100 g dry basis) and antioxidant capacity (22 μmol LE/100 g dry basis) among the by-products. This by-product of pink guava puree industry can be a potential source of lycopene and antioxidant compounds

Modelling stock selection in Malaysia based on Data Envelopment Analysis (DEA) / Md Khairu Amin Ismail

Stock selection has been a crucial puzzle to investors and abundant empirical works have looked at this issue. Nevertheless, there is very limited empirical evidence that employs DEA in stock selection. Therefore, the main purpose of the study is to apply DEA models on stock selection of Malaysian stocks. The scope of the study incorporates all firms of the five sectors of Bursa Malaysia Main Market, which are consumer, industrial, property, plantation, and trading & services. Two DEA models, technical-efficiency and super-efficiency, are utilized in modeling the DEA stock selection in Malaysia. Stock selection takes place during various economic conditions, specifically sideway-trend, upward-trend and downward-trend, covering from 1998 to 2005. The ex-post period of portfolio performance is evaluated based on 12-month (short-term) and 36-month (long-term) holding periods. The empirical findings show that, during sideway-trend selection, on average, both the DEA super-efficiency and technical-efficiency portfolios produce significantly positive abnormal returns over the long-term. However, during upward-trend selection, on average, the DEA super-efficiency portfolios exhibit significantly negative abnormal returns for both short-term and long-term periods. During downward-trend selection, the DEA super-efficiency portfolios show significantly negative abnormal returns over the long-term. The present study contributes to the literature by furnishing new empirical evidence on DEA stock selection literature as well as on the emerging market literature. Furthermore, it is also able to contribute to firms and policy makers as well. Overall, pertaining to the present findings, it is rendered that the DEA portfolios outperform over the long-term holding period particularly when the selection took place during side-way trend. This empirical finding suggests that the DEA models can be applied in Malaysia during side-way trend as a tool for helping investors in their stock selection

Effect of raw and heated flaxseed (Linum usitatissimum L.) on blood lipid profiles in rats.

Flaxseed is a nutrient rich seed and lipid profiles improving effect of it has long been studied. Effect of heating as a part of food processing on its beneficial characteristics is not clarified in literature. This study aims to provide complementary information on effect of different dosages of raw and heated flaxseed on lipid profiles. Sprague Dawley rats were fed with 10%, 20% or 30% of either raw or heated flaxseed in the basal diet for 30 days. Total cholesterol significantly reduced in all flaxseed groups and high density lipoprotein cholesterol significantly increased in 20% raw and 30% raw and heated flaxseed groups. Significant reduction of low density lipoprotein cholesterol only observed in 30% raw flaxseed groups. It is concluded that 30 days consumption of flaxseed may significantly reduce total cholesterol and increase high density lipoprotein cholesterol in blood. Oven heating may not have significant effect on lipid profile improving effect of flaxseed

Antioxidant properties of cocoa powder.

This study was aimed to determine antioxidant properties of cocoa powder. Crude cocoa extracts were fractionated using prepacked column (25 cm × 2.0 cm) with Sephadex LH 20 and an increase in water-acetone (85:15, 70:30, and 40:60, v/v) as elution. The resulting fractions 1 (F1), 2 (F2) and 3 (F3) were tested for phenolic contents, antioxidant capacity, identification of bioactive compounds liquid chromatography-mass spectrometry (LC-MS) and stability test. Theobromine and caffeine were major compounds detected in F1 and F2. Monomer, dimer and trimer were identified in F3 as m/z 289, 578 and 867, respectively. Addition of F1 and F2 could reduce antioxidant capacity of F3. Catechin and epicatechin in F3 was stable when stored at 4 and -20C for 5 months. High antioxidant capacity in F3 was likely due to the monomeric, dimeric and trimeric phenolic compounds. The presence of methylxanthines could reduce antioxidant capacity of flavonoids in cocoa powder

Therapeutic effects of vinegar: a review

Vinegar is a natural product derived from a process of fermentation. Carbohydrates-rich foods are excellent sources of substrate to produce vinegar. Vinegar is mainly used as an ingredient in food preparation due to its taste and aroma. It is one of the most famous folk medicines used to fight infections. Several studies have showed vinegar has a potential to ameliorate obesity, diabetes, cardiovascular disorders, cancer and microbial infections. Daily intake of a drink containing 15 mL vinegar (750 mg of acetic acid) was reported to improve lifestyle-related diseases, such as hypertension, hyperlipidemia, and obesity. The presence of acetic acid and other components in vinegar could be responsible for its therapeutic effect. This paper reviews recent studies on therapeutic values of vinegar derived from different food sources. Possible mechanisms of therapeutic action of vinegar are also discussed

Effect of cacao liquor extract on tumor marker enzymes during chemical hepatocarcinogenesis in rats.

This study investigated the effect of cacao liquor extract (CLE) on tumor marker enzymes-alkaline phosphatase (ALP), γ-glutamyl transpeptidase (GGT), glutathione-S-transferase (GST), and glutathione reductase (GR) activities-in plasma and/or liver of hepatocarcinogenic rats, which were induced with diethylnitrosamine and 2-acetylaminofluorene. Twenty-nine male Sprague-Dawley rats (weighing 150-330 g) were divided into four groups (n = 6-8): normal control group (N), normal group + CLE (NE), cancer group (C), and cancer group + CLE (CE). Analysis of variance showed significant differences (P < .05) in the specific activities of ALP, GGT, and GST between the C and N groups. However, GR activity for the C group was not significantly different compared with the N group. In the CE group, the specific activities of ALP, GGT, GST, and GR were significantly lower (P < .05) compared with the C group. The findings showed that CLE could lower the activity of tumor marker enzymes of rats during hepatocarcinogenesis. Based on the results obtained, polyphenol compounds present in the cacao liquor, extracted by using ethanol, have the potential in decreasing the severity of hepatocarcinogenesis

Effect of storage on beta-carotene content in Mango var. Chokanan puree

This study was aimed to determine the effect of storage on the content of â-carotene in mango puree. Mango (Mangifera indica L.) from Chokanan variety was selected for this study. The â-carotene content at 0, 3, 6 and 24 days of storage were 4.74 ± 0.29 mg/100 g puree, 3.78 ± 0.21 mg/100 g puree, 3.42 ± 0.11 mg/100 g puree and 2.84 ± 0.55 mg/100 g puree respectively. â-Carotene content of mango puree was significantly different (P < 0.05) at different storage times. However, post-hoc test showed that the â-carotene content was significantly different (P < 0.05) between day 0 and day 24 of storage times. Storage at 5 C for more than 3 days reduced 20% of â-carotene content in mango puree. Prolong storage time of the puree for more than 24 days had reduced about 40% of â-carotene content in mango puree. The study indicated that â-carotene content in mango puree was significantly lost after 24 days of storage

Antioxidant Activity of Selected Commercial Seaweeds

This study aims to evaluate the antioxidant activity (total antioxidant and free radical scavenging activities) of seaweeds commercially available in the Malaysian supermarket. Four types of seaweeds namely Nori (Porphyra sp.), Kumbu (Laminaria sp.), Wakame (Undaria sp.) and Hijiki (Hijikia sp.) were used in the study. The extracts were prepared with water and ethanol, respectively. The β-carotene bleaching and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays were used to determine antioxidant properties of seaweeds by measuring the decrease in absorbance at 470 and 517 nm. In water extract, Kumbu showed the highest total antioxidant activity of 63% compared with other samples. Kumbu, Nori and Hijiki exhibited higher radical scavenging activity than Wakame when extracted with water. Wakame exhibited the highest antioxidant and free radical scavenging activities in ethanolic extract with 58% and EC50 = 0.42 mg/ml respectively. The results of ANOVA analysis show significant differences (p<0.05) in the means of total antioxidant and free radical scavenging activities of the seaweeds. The results showed that processed commercial seaweeds exhibited varying degrees of antioxidant properties