Kassim Ali Abbas

Analysis of volatile flavour compounds and acrylamide in roasted Malaysian tropical almond (Terminalia catappa) nuts using supercritical fluid extraction

Considering the importance of tropical almond nuts as a snack item, a study was conducted to identify the flavour volatiles and acrylamide generated during the roasting of the nuts. The supercritical fluid extracted flavour components revealed 74 aroma active compounds made up of 27 hydrocarbons, 12 aldehydes, 11 ketones, 7 acids, 4 esters, 3 alcohols, 5 furan derivatives a pyrazine, and 2 unknown compounds. While low levels of acrylamide (8-86 microg/kg) were obtained in the roasted nuts, significant (P<0.05) increases occurred in concentration with increased roasting temperature and time. Carboxylic acids were the most abundant volatiles in the roasted almond nuts and less significant (P>0.05) concentration of acrylamide was generated with mild roasting and shorter roasting period.

Changing survival, memory cell compartment, and T-helper balance of lymphocytes between severe and mild asthma

BackgroundAsthma is a complicated network of inflammatory reactions. It is classified into mild, moderate, and severe persistent asthma. The success of asthma therapy relies much on understanding the underlying mechanisms of inflammation at each stage of asthma severity. The aim of this study was to explore the differences in apoptotic potential, CD4/CD8 ratio, memory compartment, and T- helper (Th) 1 and 2 profile of peripheral blood lymphocytes (PBL) in patients with mild intermittent asthma and severe persistent asthma during exacerbation periods.ResultsFour research lines were investigated and compared among mild asthmatics, severe asthmatics, and healthy groups by applying immunocytochemical staining of PBL. Antiapoptotic and proapoptotic proteins with Bcl-2/Bax ratio, CD4, CD8 markers with CD4+/CD8+ ratio, CD45RO+, CD45RA+ markers with memory/naïve ratio (CD45RO+/CD45RA+). Th2/Th1 cytokines balance represented by IL-4/IFN-γ ratio was measured by enzyme-linked immunosorbent assay (ELISA) for in vitro PBL cytokine synthesis. It was found that Bcl-2/Bax ratio was higher in severe than in mild asthmatics which in turn was higher than in healthy group. And memory/naïve ratio of PBL was higher in severe than in mild asthmatics. Moreover, memory cells, CD45RO+ and CD45RO+/CD45RA+ ratio were correlated directly with Bcl-2/Bax, in severe and mild asthma patients. In contrast, CD4+/CD8+ ratio was not changed significantly among healthy group, mild and severe asthmatics. However, CD8+ cells were correlated directly with memory cells, CD45RO+, in severe asthmatics only. Interestingly, the dominant profile of cytokines appeared to change from T helper 2 (Th2) in mild asthmatics to T helper 1 (Th1) in severe asthmatics where the lowest in vitro IL-4/IFN-γ ratio and highest IFN-γ were found.ConclusionIt was concluded that the underlying mechanisms of inflammation might vary greatly with asthma stage of severity. Mild intermittent asthma is mainly Th2 allergen-oriented reaction during exacerbations with good level of apoptosis making the inflammation as self-limiting, while in severe persistent asthma, the inflammatory reaction mediated mainly by Th1 cytokines with progressive loss of apoptosis leading to longer exacerbations, largely expanded memory cells, CD45RO+, leading to persistent baseline inflammation.

The distinctive profile of risk factors of nasopharyngeal carcinoma in comparison with other head and neck cancer types

BackgroundNasopharyngeal carcinoma (NPC) and other head and neck cancer (HNCA) types show a great epidemiological variation in different regions of the world. NPC has multifactorial etiology and many interacting risk factors are involved in NPC development mainly Epstein Barr virus (EBV). There is a need to scrutinize the complicated network of risk factors affecting NPC and how far they are different from that of other HNCA types.Methods122 HNCA patients and 100 control subjects were studied in the region of the Middle East. Three types of HNCA were involved in our study, NPC, carcinoma of larynx (CL), and hypopharyngeal carcinoma (HPC). The risk factors studied were the level of EBV serum IgG and IgA antibodies measured by ELISA, age, sex, smoking, alcohol intake, histology, and family history of the disease.ResultsEBV serum level of IgG and IgA antibodies was higher in NPC than CL, HPC, and control groups (p < 0.01). NPC was associated with lymphoepithelioma (LE) tumors, males, regular alcohol intake, and regular smoking while CL and HPC were not (p < 0.05). CL and HPC were associated with SCC tumors (p < 0.05). Furthermore, NPC, unlike CL and HPC groups, was not affected by the positive family history of HNCA (p > 0.05). The serum levels of EBV IgG and IgA antibodies were higher in LE tumors, regular smokers, younger patients, and negative family history groups of NPC patients than SCC tumors, non-regular smokers, older patients and positive family history groups respectively (p < 0.05) while this was not found in the regular alcoholics (p > 0.05).ConclusionIt was concluded that risk factors of NPC deviate much from that of other HNCA. EBV, smoking, alcohol intake, LE tumors, male patient, and age > 54 years were hot risk factors of NPC while SCC and positive family history of the disease were not. Earlier incidence, smoking, LE tumors, and negative family history of the disease in NPC patients were associated much clearly with EBV. It is proposed that determining the correct risk factors of NPC is vital in assigning the correct risk groups of NPC which helps the early detection and screening of NPC.

Distinctive Exotic Flavor and Aroma Compounds of some Exotic Tropical Fruits and Berries: A Review

The characteristic flavor of exotic tropical fruits is one of their most attractive attributes to consumers. In this article, the enormous diversity of exotic fruit flavors is reviewed. Classifying some of the exotic fruits into two classes on the basis of whether esters or terpenes predominate in the aroma was also attempted. Indeed, as far as exotic tropical fruits are concerned, the majority of fruits have terpenes predominating in their aroma profile. Some of the fruits in this group are the Amazonian fruits such as pitanga, umbu-caja, camu-camu, garcinia, and bacuri. The ester group is made up of rambutan, durians, star fruit, snake fruit, acerola, tamarind, sapodilla, genipap, soursop, cashew, melon, jackfruit, and cupuacu respectively. Also, the role of sulphur-volatiles in some of the exotic fruits is detailed.

Volatile Compounds of Roasted and Steamed Malaysian Tropical Almond Nut (Terminalia catappa L.)

The flavor extract components contributing to the characteristic aroma notes of roasted and steamed tropical almond nuts were investigated by means of gas chromatography-olfactometry and mass spectrometry of solvent extracts. Roasting and steaming data revealed all of the main classes of compounds commonly listed as thermally generated flavors in oily seeds. A total of 72 volatile compounds were identified in the sample from roasted nuts; among these were 27 hydrocarbons, 12 aldehydes, 12 ketones, 8 acids, 4 esters, 3 alcohols, 3 furans, and a pyrazine. The steamed nuts, however, yielded 66 peaks from which 63 volatile compounds were identified (22 hydrocarbons, 9 aldehydes, 9 ketones, 9 esters, 4 acids, 9 alcohols, and a pyrazine). The small number of aldehydes, ketones, pyrazine, and alcohols identified are the ones most likely to contribute to the aroma of the nuts.

Novel Epstein-Barr virus immunoglobulin G–based approach for the specific detection of nasopharyngeal carcinoma

PURPOSE This study was designed to find a reliable Epstein-Barr virus (EBV) immunoglobulin (Ig) G-based diagnostic/screening test for nasopharyngeal carcinoma (NPC) able to demarcate between the NPC-related seropositivity of EBV IgG antibodies and that of other head and neck cancer (HNCA) and control groups. The NPC-associated immunosuppression affects EBV IgA much more than IgG, leading to inconsistent detection of NPC using EBV IgA antibodies. MATERIALS AND METHODS One hundred twenty-two HNCA patients, 42 NPC, 66 laryngeal carcinoma, and 14 hypopharyngeal carcinoma and 3 groups of 100 control subjects were enrolled in this study. Enzyme-linked immunosorbent assay (ELISA) was used to find a specific cutoff value for the NPC-related seropositivity of EBV IgG antibodies. RESULTS NPC group showed higher serum level of EBV IgG antibodies than control and other HNCA groups (P < .05). However, the traditional cutoff value, mean + 2 SDs of control subjects, failed to demarcate the seropositives of NPC patients from those of healthy population (P > .05). The new cutoff value, mean + 2 SDs of the seropositives group of control subjects who had already been grouped by the traditional cutoff value, proved successful. It succeeded to demarcate between the NPC-related EBV IgG seropositivity and that issued from the persistent, latent, or reactivated EBV infection in the population (P < .05). The sensitivity/specificity of NPC detection by the new cutoff-based ELISA kit, 76.19% and 86%, was close or higher than that of EBV IgA antibodies. CONCLUSION EBV IgG-based ELISA could be used for the diagnosis of NPC using a new cutoff threshold that excludes the population baseline of EBV IgG seropositivity.

Estimation of surface film conductance during cooling of fish packages

Abstract The present paper deals with the findings of an ongoing research project regarding quality measurements in cold preserved freshwater fish. An empirical correlation, reported elsewhere, was used to design experiment for prediction of surface film conductance through transient temperature-time measurements in the fish flesh during its cooling in a chilled air duct at a constant temperature of 1°C. This surface film conductance was then used for numerical calculations of temperature variations on the basis of the finite difference method. Calculations were repeated with surface film conductance values from the Nu-Re relation most prevalently used. The two results were compared graphically at many locations inside the tested fish samples to establish that the present approach gives much improved results compared with the existing schemes available in the literature.

Thermal Diffusivity Variation Study of Cold Stored Malaysian Pangasius Sutchi at 10°C

This paper presents the use of thermal diffusivity-variation of Malaysian Pangasius Sutchi freshwater fish as a criterion to estimate the freshness in fish marketing. A homogenous specified area of a fresh fish body was cut into slices which were wrapped and preserved in a cold store of 10°C for a period of 28 days. Ansaris approach has been found earlier as an appropriate one to measure the thermal diffusivity of fish through transient cooling. The daily measurement of those slices (samples) along the muscle orientation revealed that thermal diffusivity increased up to 3 days then stayed approximately constant up to the end of the preservation period (28 days). In the literature the shelf life was also found 3 days at 10°C, which in turn agreed with the present investigation. Regression analysis was made to develop an empirical correlation between thermal diffusivity ratio and preservation time of the fish under study. This correlation could be used by food technologists as an index of deterioration of freshness or consumer acceptance