Ramani Bettoni - Academia.edu (original) (raw)

Papers by Ramani Bettoni

Bubbles in Food 2, 2008

Abstract The whey protein α-lactalbumin (ALA) is the second most abundant whey protein, and has b... more Abstract The whey protein α-lactalbumin (ALA) is the second most abundant whey protein, and has been associated with the foaming and emulsifying properties of whey proteins at low pH. The aim of this study was to understand the specific molecular changes occurring in ALA to explain the observed changes in functionality at low pH. The effect of pH on the protein structure of ALA and its surface activity was investigated in 0.1 M phosphate buffer in the presence of Ca2+. Spectroscopic measurements (circular dichroism and fluorescence) showed a gradual unfolding of the protein structure as the pH was decreased from 7 to 2. This agreed with high resolution NMR, which was used to monitor the structural changes of ALA. The surface activity of ALA was determined using the pendant drop method. The mechanical properties of the protein-stabilised interfaces were characterised using surface dilatational and surface shear rheological techniques. The results showed that even subtle changes in protein structure could cause a significant increase of the protein surface activity and surface rheology, as the pH decreased from 7 to 4, consistent with improved stabilisation in foams and emulsions. At pH values below the protein's isoelectric point the surface activity decreased, despite continued unfolding of the protein. This suggests that the pH-dependent charge on the protein controlled adsorption and stabilisation processes through the surface packing efficiency which is largely limited by electrostatic repulsion. When the pH was adjusted back to 7, most of the protein structure changes were reversible, only a very small irreversible proportion remained causing an increased surface activity and surface rheology of the protein compared to its original state, even though the irreversible proportion as too small to be observed by NMR.

This news article introduces a new COST Action entitled PEERE (TD1306), which stands for New Fron... more This news article introduces a new COST Action entitled PEERE (TD1306), which stands for New Frontiers of Peer Review (PEERE). PEERE is a trans-domain proposal which brings together researchers from various different disciplines and science stakeholders for the purpose of reviewing the process of peer review. PEERE officially began in May 2014 and will end in May 2018. Thirty-one countries, including Malta, are currently participating in the Action. In order to set the context in which this COST Action was initiated, we first look very briefly at the history of the process of peer review and various models of peer review currently in use. We then share what this COST Action hopes to achieve.

Annals of Nutrition and Metabolism, 2017

Global Food Security, 2021

Abstract Governments use food-based dietary guidelines (FBDGs) to outline what constitutes a heal... more Abstract Governments use food-based dietary guidelines (FBDGs) to outline what constitutes a healthy diet to guide their population. The potential of FBDGs to align national food-related policies and programmes is increasingly recognized but information on FBDG implementation is scarce. We conducted a key informant survey in 27 countries. Several types of implementation activities were identified within various sectors and settings, although there were few examples from low- and middle-income countries. Most countries had an official body responsible for implementation, but a strategy/plan for implementation and budget allocation were less common, and very few collected monitoring and evaluation data. We argue for a food systems approach that involves sectors beyond nutrition and health in the development and implementation of FBDGs, to facilitate the alignment of policies that aim to promote healthy eating.

Maternal & Child Nutrition, 2017

Agriculture and food systems play a central role in nutrition by supplying nutritious, healthy an... more Agriculture and food systems play a central role in nutrition by supplying nutritious, healthy and affordable foods. When integrated with nutrition education for behaviour change, agricultural interventions that supply diverse affordable foods from all food groups have great scope for improving young child and family diets. In 2014, process reviews were conducted in Cambodia and Malawi of food security projects that provided agricultural support and community-based nutrition education on improved infant and young child feeding (IYCF). In both countries, household visits were carried out with mothers/caregivers, and interviews and Focus Group Discussions (FGDs) were conducted with purposively selected project stakeholders (53 in Cambodia, 170 in Malawi), including government staff from the agriculture and health sectors. Results highlight that adoption of improved IYCF practices was facilitated by participation in nutrition education and practical cooking sessions, and supportive family and community structures. Barriers faced by families and caregivers were identified, such as women's workload and lack of access to high quality foods, namely fruits, vegetables, legumes, nuts and animal source foods. Implementation challenges regarding coordination of cross-sectoral targeting strategies and capacities of extension services to sustain community-based IYCF nutrition education need to be addressed to improve programme effectiveness and impact. The project lessons from Cambodia and Malawi are useful for integrated agriculture-IYCF nutrition education programmes to help ensure better young child nutrition outcomes.

Annals of nutrition & metabolism, 2018

The International Union of Nutritional Sciences held its 21st International Congress of Nutrition... more The International Union of Nutritional Sciences held its 21st International Congress of Nutrition in October 2017 in Buenos Aires, Argentina under the theme - From Sciences to Nutrition Security. In addition to multiple sessions on food systems and their links to diet, nutrition and health, the Congress closing lecture focused on the need to transform food systems so as to increase their capacity to provide healthy diets, making a call for greater involvement of nutrition scientists. This article presents the main messages of that lecture, providing (i) an overview of global nutrition trends and their links to diets, food environments and food systems, (ii) a synopsis of the current global momentum for food system transformation and (iii) the need for nutrition scientists to leverage this momentum in terms of increased evidence generation and policy advocacy. Key Messages: Poor quality diets are increasingly leading to the compromising of human health as never before; the prevalence...

Food Chemistry, 2016

Food composition data play a key role in many sectors and the availability of quality data is cri... more Food composition data play a key role in many sectors and the availability of quality data is critically important. Since 1984, the International Network of Food Data Systems (INFOODS) has been working towards improving food composition data quality and availability, including the development and updating of standards, guidelines and tools for food composition. FAO/INFOODS has recently published three comprehensive guidelines to improve and harmonise the compilation of data: (1) Guidelines for Food Matching, (2) Guidelines for Checking Food Composition Data prior to Publication of a User Table/Database, and (3) Guidelines for Converting Units, Denominators and Expressions. This article describes their content and development processes. Their adoption, along with additional ones planned for the future by FAO/INFOODS, should further improve the quality of published food composition data, which in turn can lead to more accurate nutrient intake estimates and more precise food labels, as well as better-targeted programs and policies.

Procedia Food Science, 2013

Food composition data play a key role in most nutrition related activities. The International Net... more Food composition data play a key role in most nutrition related activities. The International Network of Food Data Systems (INFOODS) has contributed to improving the availability and quality of food composition data worldwide. INFOODS activities include publication of regional and international food composition tables and databases (e.g., Food Composition Database for Biodiversity) and guidelines. Capacity development is an ongoing activity through postgraduate classroom courses and distance-learning modules. Training and awareness-raising through these efforts has led many sectors (e.g., agriculture, health, environment, food regulatory) to appreciate the importance of quality food composition data as the basis for policies and decision-making.

Journal of the Science of Food and Agriculture, 2011

A comprehensive review is presented of the nutrient composition for buffalo, mare, and dromedary ... more A comprehensive review is presented of the nutrient composition for buffalo, mare, and dromedary camel milks at the level of breed, and species-level data for yak, mithun, musk ox, donkey, Bactrian camel, llama, alpaca, reindeer and moose milks. Average values of nutrients were calculated and compared. Interspecies values (g 100 g −1) were 0.7-16.1 for total fat, 1.6-10.5 for protein, 2.6-6.6 for lactose, and 67.9-90.8 for water. Reindeer and moose milks had the highest fat and protein concentrations and the lowest lactose contents. Mare and donkey milks had the lowest protein and fat contents, in addition to showing the most appropriate fatty acid profile for human nutrition. Dromedary camel milk was most similar to cow milk in proximate composition. Moose milk was the richest in minerals, having values as high as 358 mg 100 g −1 for calcium, 158 mg 100 g −1 for sodium and 150 mg 100 g −1 for phosphorus. Interbreed differences of 4 g 100 g −1 were observed in total fat in buffalo, yak, mare and dromedary camel milks. Large interbreed differences were also present in the mineral contents in mare, buffalo and dromedary camel milks. By bringing together these compositional data, we hope to usefully widen the biodiversity knowledge base, which may contribute to the conservation and sustainable use of milk from underutilized dairy breeds and species, and to improved food and nutrition security, particularly in developing countries.

British Journal of Nutrition, 2012

In 1989 the Joint FAO/WHO Expert Consultation on Protein Quality Evaluation recommended the use o... more In 1989 the Joint FAO/WHO Expert Consultation on Protein Quality Evaluation recommended the use of the Protein Digestibility Corrected Amino Acid Score (PDCAAS) method for evaluating protein quality. In calculating PDCAAS, the limiting amino acid score (i.e., ratio of first limiting amino acid in a gram of target food to that in a reference protein or requirement) is multiplied by protein digestibility. The PDCAAS method has now been in use for 20 years. Research emerging during this time has provided useful data on various aspects of protein quality evaluation that has made a review of the current methods used in assessing protein quality necessary. This paper provides an overview of the use of the PDCAAS method as compared to other methods and addresses some of the key challenges that remain in regards to protein quality evaluation. Furthermore, specific factors influencing protein quality including the effects of processing conditions and preparation methods are presented. Protei...

American Journal of Potato Research, 2019

Potatoes play an important role developing countries' food security; 50% of the world's food ener... more Potatoes play an important role developing countries' food security; 50% of the world's food energy needs are supplied by potatoes, rice, wheat and maize. Developing countries' share of global potato output now surpasses that of developed countries. Global potato consumption was on average 35 kg/capita/yr. in 2013, with large regional differences. Trends in potato consumption show that while in Europe potato consumption has been steadily decreasing, Africa and Asia have seen a~70% increase between 1961 and 2013. Potato biodiversity is vast; variety is one of the main factors governing nutrient content. Potatoes are fat free, a source of vitamin C and vitamin B6, and can also supply good amounts of other micronutrients and fiber. Potatoes feature in the food-based dietary guidelines (FBDGs) of many countries. Some FBDGs make a distinction, recommending consumption of healthy preparations while limiting that of unhealthy forms high in energy, salt and fat. Resumen Las papas juegan un papel importante en la seguridad alimentaria de los países en desarrollo; el 50% de las necesidades mundiales de energía de los alimentos las suministra la papa, el arroz, el trigo y el maíz. Lo que comparten los países en desarrollo de la contribución mundial de papa ahora sobrepasa a lo que corresponde de los países desarrollados. El consumo global de la papa estaba en un promedio de 35 kg/cápita/año en 2013, con grandes diferencias regionales. Las tendencias en el consumo de la papa muestran que mientras que en Europa el consumo de papa ha estado disminuyendo establemente, Africa y Asia han visto un~70% de aumento entre 1961 y 2013. La biodiversidad de la papa es muy amplia; el aspecto varietal es uno de los principales factores que gobiernan el contenido de nutrientes. Las papas estan libres de grasa, son una fuente de vitamina C y de vitamina B6, y también pueden suministrar buenas cantidades de otros micronutrientes y fibra. Las papas están presentes en las guías de dietas alimenticias (FBDGs) de muchos países. Algunas FBDGs hacen una distinción, recomendando el consumo de preparaciones sanas mientras que limitan las de formas no sanas, altas en energía, sal y grasas.

BMJ (Clinical research ed.), Jan 13, 2018

Food Chemistry, 2014

Residue-specific information on the urea-induced unfolding of the molten globule state of bovine ... more Residue-specific information on the urea-induced unfolding of the molten globule state of bovine alpha-lactalbumin (BLA) has been obtained using NMR spectroscopy. In agreement with previous studies on human alpha-lactalbumin (HLA) the unfolding process for BLA has been found to be non-cooperative. Both the alpha and beta-domains of the protein are substantially collapsed in the absence of denaturant but in both proteins the majority of the structure in the beta-domain unfolds prior to that in the alpha-domain. However, in BLA the protein unfolds completely in 10 M urea at 50 degrees C, whilst in HLA a stable core region persists even under these extreme conditions. Previous studies on HLA have identified eight residues that are crucial for the stability of the molten globule. Of these residues, only three are conserved in the sequence of BLA. By taking into consideration the differences in inter-residue contacts between the four alpha-helices arising from these substitutions, and th...

Biochemistry, Mar 1, 2008

Biochemistry, 2009

Thermal and chemical modification of protein structures is known to affect their interfacial acti... more Thermal and chemical modification of protein structures is known to affect their interfacial activity. We have looked in detail at the effect of heating on the structure and subsequently the surface properties of LTP1, a nonspecific lipid transfer protein from barley, both in the presence and in the absence of its lipid adduct. CD and NMR spectroscopy showed that some of the protein molecules refold back to the native state structure after being heated to 100 degrees C for 2 h. However, for a proportion of the molecules, the structure of the protein was irreversibly unfolded which resulted in an increase in surface activity irrespective of the presence of the lipid adduct. These molecules show an increase in surface activity, which is normally associated with an increase in molecular flexibility and surface hydrophobicity and is a property that has been shown to be highly sensitive to structural changes. This explains why thermal and chemical modification of LTP1 is important in optimizing the surface properties of the protein that are essential in diverse applications from biosensors to beer foam.