Gamma radiation preserves chemical and bioactive properties of Boletus edulis wild mushrooms

Boletus edulis Bull: Fr. is an edible mushroom quite appreciated for its organoleptic and nutritional properties. However, the seasonality and perishability cause some difficulties in its distribution and marketing in fresh form; losses associated with this type of food during marketing can reach 40% [1]. Irradiation is recognized as a safe and effective method for food preservation, being used worldwide to increase shelf life of fresh and dehydrated products (e.g. fruits, vegetables and spices) [2]. In particular, gamma irradiation has already been applied to cultivated mushrooms (especially Agaricus, Lentinula and Pleurotus Genus) and proved to be an interesting conservation technology [3]. However, the studies with added-value wild species are scarce. In this work, the effects of gamma irradiation on chemical and antioxidant properties of wild B. edulis, were evaluated. Fruiting bodies were obtained in Trás-os-Montes, in the Northeast of Portugal, in November 2012. The irradiation was performed in experimental equipment with 60Co sources at 1 and 2 kGy. All the results were compared with nonirradiated samples (control). Macronutrients and energy value were determined following official procedures of food analysis; fatty acids were analyzed by gas-chromatography coupled to flame ionization detection (GC-FID), while sugars and tocopherols were determined by high performance liquid chromatography (HPLC) coupled to refraction index (RI) and fluorescence detectors, respectively. Antioxidant activity was evaluated in the methanolic extracts by in vitro assays measuring DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity, reducing power, inhibition of β- carotene bleaching and inhibition of lipid peroxidation using thiobarbituric acid reactive substances (TBARS) assay. Total phenolics were also determined by the Folin-Ciocalteu assay. The nutritional profiles were not affected in high extension. Fatty acids and sugars were slightly affected, decreasing with the increasing doses. The performed assays for antioxidant activity, indicate that irradiated samples tended to have lower scavenging activity and reducing power, but higher lipid peroxidation inhibition. Despite the detected differences in individual compounds, the results of nutritional parameters, the most relevant in terms of mushroom acceptability by consumers, were less affected, indicating an interesting potential of gamma-irradiation to be used as an effective conservation technology for the studied mushrooms.

Advanced decision-support methods for the design, control, and optimization of perishable products life cycle

In the last decades, global food supply chains had to deal with the increasing awareness of the stakeholders and consumers about safety, quality, and sustainability. In order to address these new challenges for food supply chain systems, an integrated approach to design, control, and optimize product life cycle is required. Therefore, it is essential to introduce new models, methods, and decision-support platforms tailored to perishable products. This thesis aims to provide novel practice-ready decision-support models and methods to optimize the logistics of food items with an integrated and interdisciplinary approach. It proposes a comprehensive review of the main peculiarities of perishable products and the environmental stresses accelerating their quality decay. Then, it focuses on top-down strategies to optimize the supply chain system from the strategical to the operational decision level. Based on the criticality of the environmental conditions, the dissertation evaluates the main long-term logistics investment strategies to preserve products quality. Several models and methods are proposed to optimize the logistics decisions to enhance the sustainability of the supply chain system while guaranteeing adequate food preservation. The models and methods proposed in this dissertation promote a climate-driven approach integrating climate conditions and their consequences on the quality decay of products in innovative models supporting the logistics decisions. Given the uncertain nature of the environmental stresses affecting the product life cycle, an original stochastic model and solving method are proposed to support practitioners in controlling and optimizing the supply chain systems when facing uncertain scenarios. The application of the proposed decision-support methods to real case studies proved their effectiveness in increasing the sustainability of the perishable product life cycle. The dissertation also presents an industry application of a global food supply chain system, further demonstrating how the proposed models and tools can be integrated to provide significant savings and sustainability improvements.

Kinetic and mechanistic studies on unconventional antioxidant activities of natural compounds

In chapter one, the autoxidation kinetics of natural oil substrates, including, triglyceric sunflower oil, olive oil, terpenic squalene, and p-cymene were calibrated through differential oximetry methods. Calibration allows their use as reference oxidizable substrates for further studies, e.g. for quantitative testing of antioxidants under biomimetic settings. Several essential oils samples, of different botanical species or different productions of same species were studied for their antioxidant activity in inhibited autoxidation kinetics. Their antioxidant activities were matched with their composition analyzed by GC-MS. In chapter two, the molecular mechanism of the synergy between the common phenolic antioxidants such as tocopherol and catechols with widespread essential component gamma-terpinene was studied through lipid oxidation kinetics. Wherein, gamma-terpinene was able to disclose the key intermediacy HOO·, which acted as a reducing agent regenerating the phenolic antioxidant. This counterintuitive role of HOO· radicals was further investigated in detail and allowed to rationalize for the first time the purported antioxidant behavior of PDA melanin nanoparticles. It will also open to a deeper understanding of the redox biology of quinones. Regarding melanin, its role is broadly important in living organisms and its control, including its inhibition, is of great importance with several relevant applications ranging from food preservation to control of human skin pigmentation. In chapter three, an oximetry method combined with the traditional UV-Vis spectroscopy was developed to study the tyrosinase inhibition kinetics, which allowed identifying Glabridin (from G. glabra, L.), as one of the most effective natural tyrosinase inhibitors.

A system of uniform and common international regulations for the protections and preservation of the food fishes in international boundary waters of the United States and Canada /

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Determination of parathion and carbaryl pesticides in water and food samples using a self assembled monolayer/acetylcholinesterase electrochemical biosensor

An acetylcholinesterase (AchE) based amperometric biosensor was developed by immobilisation of the enzyme onto a self assembled modified gold electrode. Cyclic voltammetric experiments performed with the SAM-AchE biosensor in phosphate buffer solutions ( pH = 7.2) containing acetylthiocholine confirmed the formation of thiocholine and its electrochemical oxidation at E-p = 0.28 V vs Ag/AgCl. An indirect methodology involving the inhibition effect of parathion and carbaryl on the enzymatic reaction was developed and employed to measure both pesticides in spiked natural water and food samples without pre-treatment or pre-concentration steps. Values higher than 91-98.0% in recovery experiments indicated the feasibility of the proposed electroanalytical methodology to quantify both pesticides in water or food samples. HPLC measurements were also performed for comparison and confirmed the values measured amperometrically.

Methods for effective fluidization of particulate food materials

Depending on the size and shape of the materials, methods employed to achieve effective fluidization during fluid bed drying varies from use of simple hole distributors for small, light weight materials to special techniques for lager and/or moist materials. This paper reviews common air distributors used in fluidized bed drying of food particulates. Also it reviews special methods of fluidizing larger irregular food particulates.

The Oncological and Functional Risks of the Organ Preservation Experimental Treatment Approach

We increasingly face conservative surgery for rectal cancer and even the so called ‘wait and see’ approach, as far as 10–20% patients can reach a complete pathological response at the time of surgery. But what can we say to our patients about risks? Standard surgery with mesorectal excision gives a <2% local recurrence with a post operative death rate of 2–8% (may reach 30% at 6 months in those over 85), but low AR has some deterioration in bowel function and in low cancer a permanent stoma may be required. Also a long-term impact on urinary and sexual function is possible. Distant metastasis rate seem to be identical in the standard and conservative approach. It is difficult to evaluate conservative approach because a not clear standardization of surgery for low rectal cancer. Rullier et al tried to clarify, and they found identical results for recurrence (5–9%), disease free survival (70%) at 5y for coloanal anastomosis and intersphinteric resection. Other series have found local recurrence higher than with standard approach and functional results may be worse and, in some situations, salvage therapy is compromised or has more complications. In this context, functional outcomes are very important but most studies are incomplete in measuring bowel function in the context of conservative approach. In 2005 Temple et al made a survey of 122/184 patient after sphinter preserving surgery and found a 96.9% of incomplete evacuation, 94.4% clustering, 93.2% food affecting frequency, 91.8% gas incontinence and proposed a systematic evaluation with a specific questionnaire. In which concerns ‘Wait and see’ approach for complete clinical responders, it was first advocated by Habr Gama for tumors up to 7cm, with a low locoregional failure of 4.6%, 5y overall survival 96%, 72% for disease free survival; one fifth of patients failed in the first year; a Dutch trial had identical results but others had worse recurrence rates; in other series 25% of patients could not be salvaged even with APR; 30% have subsequent metastatic disease what seems equal for ‘wait and see’ and operated patients. In a recent review Glynne Jones considers that all the evaluated ‘wait and see’ studies are heterogeneous in staging, inclusion criteria, design and follow up after chemoradiation and that there is the suggestion that patients who progress while under observation fare worse than those resected. He proposes long-term observational studies with more uniform inclusion criteria. We are now facing a moment where we may be more aggressive in early cancer and neoadjuvant treatment to be more conservative in the subsequent treatment but we need a better stratification of patients, better evaluation of results and more clear prognostic markers.

Advances in preservation of fruits and vegetables with bioactive coatings

Bioactive compounds are a large group of compounds (antimicrobials, antioxidants, nutrients, etc.), but its use in edible fi lms and coatings for application on fruits and vegetables has been very important because nowadays the consumers demand fruits and vegetables that are fresh, healthy, high quality and easy to prepare. A number of investigations have shown that the use of additives in edible fi lms and coatings improve its functionability and provide compounds for human health. However, it is necessary to continue research that can generate specifi c or tailor-made edible fi lms and coatings for each product with the best characteristics for preservation. In this review we present and analyze the concepts, progress and perspectives in the design and application of edible fi lms and coatings for fruits and vegetables in order to defi ne the challenges and opportunities that this topic of study in the fi eld of science, technology and food engineering.

Development of nanohydrogels as a vehicle for the release of bioactive compounds in food matrices

PhD in Chemical and Biological Engineering

Can calories from ethanol contribute to body weight preservation by malnourished rats?

Our objective was to compare the use of calories from ethanol by well-nourished and malnourished rats in terms of body weight. Female Wistar rats weighing 170-180 g at the beginning of the study were used. The animals were divided into two groups (N = 12 each): group W received water ad libitum and group E an ethanol solution ad libitum as the only source of liquid throughout the experiment. The concentration of ethanol was increased weekly from 0 to 5, 10, 20 and 40% (v/v). In the well-nourished phase (A), all rats received food ad libitum (AW and AE). Ethanol treatment (AE) was then interrupted and water was offered to both groups. After 2 weeks both AW and AE rats were submitted to food restriction (50% of group AW food consumption), thus initiating the malnutrition phase (M). Liquid was offered as described before to the same W (MW) and E (ME) groups. The weight gain during the 1-week treatment of AE rats was similar to that of AW animals only when AE rats received the 5% (v/v) ethanol solution (9.16 vs 10.47 g). Weight loss was observed after exposure to 10% ethanol (P < 0.05) in spite of maintenance of caloric intake. Malnourished rats presented weight loss, which was attenuated by ethanol intake up to the 20% (v/v) solution and was related to an increased caloric offer. This effect was not observed with the 40% ethanol solution (-9.98 g). These data suggest that calories from ethanol were used to maintain body weight up to the concentration of 10% (v/v) (well-nourished) and 20% (v/v) (malnourished) and that ethanol has a toxic profile which depends on nutritional status.

Quality of Canned mandarin as affected by preservation liquid

This study is integrated within a research line dedicated to evaluate different options to introduce mandarin in Spanish agro-food industries and in both national and international markets. The effects of different preservation liquids (sucrose solution, sucrose and ascorbic acid solution, grape, and grapefruit juices), soluble solids (10, 12, 14 ºBrix), and thermal processing (30 seconds at 98 ºC) on vitamin C, color, carotenoids and sensory quality of canned Satsuma mandarin segments were studied. The liquid preservation that presented the best results was grapefruit juice, which provided the highest vitamin C (323 mg.L-1) and total carotenoids (16.4 mg.L-1) contents (the main carotenoid found was β-cryptoxanthin), intense orange color, high thermal stability, and very good sensory quality (e.g. intense floral and fresh-mandarin aromas and low levels of off-flavors).

O movimento Slow Food e seus impactos para a produção do queijo artesanal na região do Alto Paranaíba - Minas Gerais

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Food-safety hazards in the pork chain in Nagaland, North East India: implications for human health.

Pork occupies an important place in the diet of the population of Nagaland, one of the North East Indian states. We carried out a pilot study along the pork meat production chain, from live animal to end consumer. The goal was to obtain information about the presence of selected food borne hazards in pork in order to assess the risk deriving from these hazards to the health of the local consumers and make recommendations for improving food safety. A secondary objective was to evaluate the utility of risk-based approaches to food safety in an informal food system. We investigated samples from pigs and pork sourced at slaughter in urban and rural environments, and at retail, to assess a selection of food-borne hazards. In addition, consumer exposure was characterized using information about hygiene and practices related to handling and preparing pork. A qualitative hazard characterization, exposure assessment and hazard characterization for three representative hazards or hazard proxies, namely Enterobacteriaceae, T. solium cysticercosis and antibiotic residues, is presented. Several important potential food-borne pathogens are reported for the first time including Listeria spp. and Brucella suis. This descriptive pilot study is the first risk-based assessment of food safety in Nagaland. We also characterise possible interventions to be addressed by policy makers, and supply data to inform future risk assessments.