Elsa Vieira

Chromium speciation analysis in bread samples.

Chromium is a controversial element with important essentiality and toxicity, depending on its different species; its speciation analysis in principal human foodstuffs, as in the case of bread, is of utmost importance. With this purpose, a method was validated, including a wet acid digestion procedure for total chromium dissolution, a selective alkaline extraction of hexavalent chromium, and ETAAS determination. The method was applied to the determination of total and hexavalent chromium in 152 bread samples. The total chromium contents were 47.3 +/- 20.0 and 50.9 +/- 22.2 microg/kg of dry weight for white and whole bread samples, respectively; those for hexavalent chromium were 5.65 +/- 5.44 and 6.82 +/- 4.88 microg/kg of dry weight. On the basis of a mean daily ingestion of three bread units, the calculated daily intake was up to 12.7 microg/day for total chromium and 1.98 microg/day for hexavalent chromium. Referring to total chromium, bread can contribute up to 10% of the Reference Daily Intake, 120 microg/day.

Quantification of total and hexavalent chromium in lager beers: variability between styles and estimation of daily intake of chromium from beer.

A survey of the presence of total and hexavalent chromium in lager beers was conducted to understand the variability between different styles of lager beer packaged in glass or cans and to estimate daily intake of total Cr and hexavalent chromium from beer. Graphite-furnace atomic absorption spectroscopy using validated methodologies was applied. Selective extraction of hexavalent chromium was performed using a Chromabond NH2/500 mg column and elution with nitric acid. The detection limits were 0.26 and 0.68 μg L(-1) for total Cr and Cr(VI), respectively. The mean content of total Cr ranged between 1.13 μg L(-1) in canned pale lager and 4.32 μg L(-1) in low-alcohol beers, whereas the mean content of Cr(VI) was <2.51 μg L(-1). Considering an intake of 500 mL of beer, beer consumption can contribute approximately 2.28-8.64 and 1.6-6.17% of the recommended daily intake of chromium for women and men, respectively.

Antioxidant and antihypertensive hydrolysates obtained from by-products of cannery sardine and brewing industries

abstract Hydrolysates with antioxidant and antihypertensive activities were obtained from sarcoplasmic proteins of canned sardine by-product and proteases extracted from Brewer’s spent yeast. Using response surface methodology, hydrolysis time and temperature were selected to achieve the maximum bioactivity. Hydrolysates produced using the substrate/enzyme ratio 1:0.27 (mg/U), 7 h and 50ºC, presenting an angiotensin I-converting enzyme-inhibitory activity of 164 µg protein/mL and an antioxidant activity of 293 μM TE/mL. Experimental results agreed with predicted values within a 95% confidence interval. Within this work the simultaneous valorisation of two agro-industrial by-products was successfully achieved.

SousChef: Mobile Meal Recommender System for Older Adults.

Nowadays, following a healthy diet is a challenge, either due to the large variety of food and ingredient combination possibilities or due to the lack of knowledge required to make healthy choices. This problem is even more patent amongst older adults. Although some recommender systems and applications have been proposed with aim to monitor calorie consumption and/or to suggest healthy recipes to general consumers, no similar solution was yet presented focused on older adults’ needs. In this work, a mobile meal recommender system, SousChef, for this target group is presented. This system is capable of creating a personalized meal plan based on the information provided by the user, including the anthropometric measures, personal preferences and activity level. The nutritional recommendations and the application was thought and designed for older adults, presenting friendly user interfaces and following the guidelines of a nutritionist. Tests with users were conducted in order to ascertain recipe and nutritional plan suitability as well as usability of the mobile application. Results showed that more than 70% of the older adult participants were satisfied with the meal plan suggestions and with the simplicity of the SousChef

Chayote (Sechium edule): A review of nutritional composition, bioactivities and potential applications

Chayote (Sechium edule) has gained widespread consuming acceptance and recognized by its nutritional and bio-functional properties. The present review surveys and describes the current findings about the nutritional, phytochemical and pharmacological properties of chayote and identifies opportunities for further research. It also discusses chayotes versatile utility in nutrition, as a functional ingredient in food, cosmetic and pharmaceutical industries, as well as in nanotechnology and biotechnological processes. It was concluded that although the pharmacological properties of chayote are currently well-established, only a few reports have been conducted on the isolation and identification of individual chemical constituents, and similarly, only a few in vivo studies have been conducted to assess their biological efficacy. In addition, the valorisation of the underutilized chayote by-products can be an important aspect in waste management from both economic and environmental standpoints. Thus, the recovery and utilization of valuable compounds from chayote is an important challenge for scientists.

Bio‐functional properties of sardine protein hydrolysates obtained by brewer's spent yeast and commercial proteases

BACKGROUND The canned-sardine industry generates large amounts of protein-rich waste, which demands useful exploitation. This paper describes the potential use of muscle and viscera proteins from canned sardine by-products as substrate to obtain hydrolysates with biological and functional properties. Three enzymatic approaches, brewers spent yeast (Bsy) proteases, Alcalase® and Neutrase® were applied to perform protein hydrolysis at the same proteolytic activity (1 U mL-1 ), using an enzyme/substrate ratio of 20% (v/v), at 50°C and for 7 h. Hydrolysis degree (DH), antioxidant and angiotensin I-converting enzyme inhibitory (ACE-I) activities, functional properties (i.e. solubility, emulsifying and foaming properties, water and oil binding capacity) and colour were investigated. RESULTS All hydrolysates presented a high protein content [52.7-83.2% dry weight (DW)] and low fat content (0.9-3.9% DW). Alcalase® treatment of muscle and viscera proteins resulted in higher DH (7.5% and 8.6%, respectively) and higher biological activities (P < 0.05). All hydrolysates had excellent solubility and presented functional properties. Among viscera hydrolysates, treatment with Bsy proteases promoted higher emulsion (80.1 m2 g-1 ), foaming (79.2%) and oil binding capacity (5.8 g g-1 ) of viscera sardine proteins. CONCLUSION Improved biological and functional properties were observed for sardine protein hydrolysates produced using the three enzymatic treatments tested.

Seaweeds from the Portuguese coast: A potential food resource?

The Portuguese coast presents a large amount of potentially edible seaweeds that are underexploited. The identification of different macroalgae species and their availability in the northern and central coast of the continental territory was assessed. The nutritional value of seaweeds is discussed based on a literature review (when available) focused on data for species collected in Portugal with the aim to define the most important nutritional parameters that should be characterized in the samples. Possible health concerns related with the presence of contaminants are also considered.