Mastication effects on carotenoid bioaccessibility from mango fruit tissue

The release of carotenoids from fresh fruits or vegetables is determined by the encapsulating plant tissue matrix, intracellular carotenoid location within the cell, and the mastication process. The objectives of this study were to assess the particle sizes obtained after mastication of mango fruit tissue, and how the resulting degree of plant tissue rupture affects carotenoid bioaccessibility. A fine and a coarse chewer were selected after screening 20 healthy volunteers for in vivo human mastication, and the collected chewed boluses were subjected to wet sieving fractionation, followed by an in vitro gastric and small intestinal digestion model. Confocal micrographs show that the smallest particle size fraction (0.075 mm) consists mostly of fragmented cells and the largest size fraction (2.8 mm) contains bulky clusters of whole cells and vascular fibers. Higher amounts of total carotenoids (211–320 μg/100 g) were observed in the larger particle size fraction (2.8 mm) relative to the 1 mm (192–249 μg/100 g) and 0.075 mm fractions (136–199 μg/100 g). Smaller particles showed a greater % release of total carotenoids after in vitro digestion. Xanthophyll derivatives are more bioaccessible than β-carotene for all particle sizes. The effects of particle size or degree of fine vs coarse chewing are unexpectedly small (p > 0.05), but the process of chewing substantially reduced the release of β-carotene and xanthophylls by 34% and 18%, respectively. While there is a (small) particle size effect, this appears to not be the primary factor controlling bioaccessibility for soft tissues such as mango, in contrast to previous reports that a single cell wall appears to be enough to prevent bioaccessibility of carotenoids in more robust carrot tissues

Very fast chilling modifies the structure of muscle fibres in hot-boned beef loin

The aim of this study was to gain a better understanding of the tenderisation mechanism associated with very fast chilling (VFC) of beef muscle. Hot-boned striploins from 36 carcasses were allocated to a treatment (control, delayed or immediate chilling below 0 °C), and each striploin was divided into three equal portions and allocated to a time post-mortem (2, 5 or 14 d). Immediate chilling resulted in lower peak force values at 2 d post-mortem and lower particle size after 5 d post-mortem. Both chilling treatments significantly improved the WHC by reducing drip loss and cooking loss. Sarcomere lengths were not affected by chilling treatments, although fragmentation and cleavage of muscle fibres were evident along the fibre length, possibly contributing to the reduction in peak force values at 2 d post-mortem. Both delayed and immediate chilling resulted in a higher pH at 4 and 24 h post-mortem, and colour parameters were modified. These results suggest that VFC has potential for accelerating tenderisation early post-mortem by a combination of biochemical and biophysical effects

In vitro biodegradation of hepatotoxic indospicine in Indigofera spicata and its degradation derivatives by camel foregut and cattle rumen fluids

The known accumulation of the hepatotoxin indospicine in tissues of camels and cattle grazing Indigofera pasture plants is unusual in that free amino acids would normally be expected to be degraded during the fermentation processes in these foregut fermenters. In this study, in vitro experiments were carried out to examine the degradability of indospicine of Indigofera spicata by camel and cattle foregut microbiota. In the first experiment, a 48 h in vitro incubation was carried out using foregut fluid samples that were collected from 15 feral camels and also a fistulated cow. Degradability of indospicine ranged between 97 − 99% with the higher value of 99% for camels. A pooled sample of foregut fluids from three camels that were on a roughage diet was used in a second experiment to examine the time-dependent degradation of indospicine present in the plant materials. Results indicated that camels’ foregut fluids have the ability to biodegrade approximately 99% of the indospicine in I. spicata within 48 h of incubation and produced 2-aminopimelamic acid and 2-aminopimelic acid. The time-dependent degradation analysis showed rapid indospicine degradation (65 nmol/h) during the first 8−18 h of incubation followed by a slower degradation rate (12 nmol/h) between 18 h and 48 h. Indospicine degradation products were also degraded towards the end of the experiment. The results of these in vitro degradation studies suggest that dietary indospicine may undergo extensive degradation in the foregut of the camel resulting in trace levels after 48 hours. The retention time for plant material in the camel foregut varies depending on feed quality, and the results of this study together with the observed accumulation of indospicine in camel tissues suggests that although indospicine can be degraded by foregut fermentation, this degradation is not complete before the passage of the digesta into the intestine

The Development of Accounting in the Franc Zone Countries in Africa

This paper develops a taxonomy of the different accounting systems that have evolved in Africa from the colonial era, through the early years of independence, to modern times. A preliminary test of the classification scheme for the current era of International Financial Reporting Standards (IFRS) was carried out using data from a PricewaterhouseCoopers (2011) survey. The results confirm Nobes’ (2008) hypotheses on patterns of national reaction to IFRS. The results also show that a distinctive approach to financial accounting, which is alien to Anglo-American practitioners, and modelled on long-established French traditions, is still entrenched in Africa’s franc zone countries in the 21st century despite sustained pressure from the World Bank and the International Monetary Fund for large entities to adopt IFRS. These findings provide some evidence against Alexander and Archer’s (2000) claim that the contemporary notion of “Anglo-Saxon accounting” is a myth

How Media Ecologies Can Address Diverse Student Needs

Post-secondary education sees an increasing variety of instructional media and an increasing diversity among learners. The goal of this study was to ascertain whether students of different learning styles, majors, and genders benefited from particular instructional media. Students completed a learning styles inventory and a survey of perceived usefulness of each instructional medium. Qualitative information was collected in student focus groups. All students perceived some of the same instructional media as useful and all valued a mix of media. A rich ecology of media appears to enhance student learning.published or submitted for publicationis peer reviewe

Redesigning the Learning Objectives for Use of Web-based Learning Modules in Plants, Pathogens, and People (PLPA 200)

A study was undertaken to evaluate the use of web-based laboratory activities on student comprehension of the scientific method in Plants, Pathogens, and People (PLPA 200), a general education course that fulfills requirements for advanced composition and natural science. At the beginning of the Fall 2006 and Spring 2007 semesters students in PLPA 200 were given a pre-test to determine their level of competence in describing and applying the scientific method. They were then assigned a series of virtual lab experiments, asked to reflect on those experiments, and given a post-test to ascertain if their competence had improved. Comparing pre- and post-test results, overall student scores on post-tests were significantly higher than their pre-test scores. For individual questions, scores for 10 of the 13 questions were significantly higher on the post-test. Improvement was seen on 6 of 7 questions asking for general descriptions, such as "What is a scientific observation?" Scores improved on 4 of 6 questions that asked for specific information, such as "Write a specific hypothesis for this experiment." Pre- and post-test scores were not found to be associated with the students’ gender or major (science vs. non-science, or agriculture vs. non-agriculture). These findings indicate that students' use of the PPP web site did result in an increase in both their ability to describe the general concepts of the scientific method and their ability to apply that knowledge to specific situations.University of Illinois Provost's Initiative on Teaching Advancement (PITA)unpublishednot peer reviewe

Nutriomic analysis of fresh and processed fruit products. 2. During in vitro simultaneous molecular passages using Caco-2 cell monolayers

Many studies have used Caco-2 cell monolayers as human intestinal absorption models. However, only a few studied digested foods, instead of pure standard compounds. Moreover, beneficial and nutritional molecules (nutriome) have not been investigated simultaneously. The present study explored nutriome passages from digest solution of fresh, dried, and juiced tomato, mango, and papaya using Caco-2 cell monolayers in apical-basolateral directions. A validation method using complementary TEER and P,,pp values or internal standard caffeine is recommended because physiologically passive diffusion is unlikely to happen. Sugars were transported into basolateral sides, resulting in potential glucose equivalent bioavailability of 2.26-75 mg h(-1)/100 g (WB). Using sugar passage rates (DB) of juices as 100% references, the rate order was tomato (49.8% dried; 89.5% fresh) > mango (56.8% dried; 22.8% fresh) > papaya (18.7% dried; 36.7% fresh). Major indications that phytochemical absorption does not occur in the small intestine were obtained from the bioassay condition selected. Apical organic acid levels decreased, which occasionally were transported into basolateral sides, whereas the disappearances of apical carotenoids and phenolics were not. Pectin substances were predicted to be responsible for the disappearances of bioactive compounds in those pectin-rich fruits. Further investigations on the role of pectin substances in intestinal passages are recommended

Flavour retention during high temperature short time extrusion cooking process: a review

Research on the stability of flavours during high temperature extrusion cooking is reviewed. The important factors that affect flavour and aroma retention during the process of extrusion are illustrated. A substantial number of flavour volatiles which are incorporated prior to extrusion are normally lost during expansion, this is because of steam distillation. Therefore, a general practice has been to introduce a flavour mix after the extrusion process. This extra operation requires a binding agent (normally oil), and may also result in a non-uniform distribution of the flavour and low oxidative stability of the flavours exposed on the surface. Therefore, the importance of encapsulated flavours, particularly the beta -cyclodextrin-flavour complex, is highlighted in this paper