The European population, as well as many other populations across the world, has been ageing since the ‘50s and prospects show that this trend will be increasing in the next decades with a peak in 2040. Facing this problem in a decent while economically-efficient way is a challenge posed to almost all European countries, according to the European Innovation Partnership on Active and Healthy Ageing.
Malnutrition, which particularly affects older people, costs European healthcare systems similar amounts as obesity and overweight, and is a major determinant in accelerated loss of autonomy and adverse health outcomes. However up until now, elderly malnutrition is fought at the quantitative level by elderly food pyramid-based prescriptions or food supplements.
With the aim to fight the onset of elderly malnutrition by achieving a paradigm shift rather than remedying elderly nutritional deficiencies, the project Optifel was established. It is a European project funded under the Seventh Framework Program. It brings together 26 partners from France, Poland, Spain, Poland, Switzerland, Belgium, Turkey and the United Kingdom, with public laboratories, small and medium companies and large businesses. It has a total budget of €4.5 million (US$5.02 million) for a EU grant of €3 million (US$3.35 million) and lasts 42 months, from September 2013 to February 2017.
The project will contribute to fight appetite loss with attractive and nutrient-dense food products designed to meet the nutritional needs, sensory expectations and physical constraints at the level of end-products as well as preparation and delivery.
To design the products, the project will map all the relevant information on elderly’s needs, expectations, capabilities of handling and manipulating product and packaging, and acquire data on the evolution of taste sensitivity (for attractiveness) as well as physical capacities (ease of chewing, ease of opening) with ageing.
This will provide data to guide further product development and contribute to design a new generation of varied and tasty food products for elderly and thus help improve life quality and push back hospitalisation. The project will test the developed concepts using fruit and vegetables as a base, and has today already revealed a number of findings regarding food preferences, packaging preferences, sensory capabilities of elderly, and more.
A first part of the project concerned identification of preferences and needs, and their evolutions with ageing. A major achievement was a survey of preferences concerning fruits, vegetables, and food products from fruit and vegetables, allowing an assessment of common aspects and cultural differences. This survey included over 400 elderly and 45 care-caterers and was carried out in France, Finland, United Kingdom, Poland, Span and Turkey, involving eight of the project’s partners and a common (translated) questionnaire.
Fruit and vegetable foods got good scores from elderly. Sauces, spices and seasonings did not seem to be well liked. Differences between countries in terms of preferred products were large, however overall least disliked fruits were peach, plum, apple, pear and strawberry, and least disliked vegetables were green peas, lettuce, green cabbage, raw tomato and cooked carrot.
Different levels of food neophobia (the fear of eating new or unfamiliar foods) among elderly were observed in different countries. The elderly prefer simple dishes and food that should be traditional, designed with the elderly’s liking in mind with ingredients familiar to elderly persons. The food should be well-cooked, tender and soft: it has to be easy to eat. Problems were caused by tough meat, hard or big food pieces, dry food stuffs, runny and broth food and foods with seeds.
For packaging, a focus group approach was used to identify with elderly persons the optimal packaging type and maximal acceptable force or torque needs for its opening. These focus groups were also used to study factors that impact legibility of information on packaging and coordinated with the survey on preferences.
Ease of opening was associated larger screw-caps, standup pouches with perforations, aluminium foil for peel-able packaging as it allows good grip. Further, labelling needs sufficient font size (larger than 1.5 mm), familiar and sans serif characters, clear contrasts and a structured layout.
Another concern was elaboration of tools to identify the eating capability of individual seniors so as to tailor foods to capabilities. Elderly subjects could be grouped into four groups based on their eating capability scores.
Elderly of the first three groups perceived food products with more hardness and/or fibrous structure as difficult to process orally. The observed relationship between hand and oro-facial muscle strengths provided a possibility of using non-invasive hand gripping force measurement for eating capability assessment.
Bite force differed by eating capability group, and was significantly affected by dental status. It influenced both liking and number of chews. Oral residence time was significantly correlated with number of chews, liking and difficulty perceived, however elderlies were in some measure able to adapt number of chews as a palliative for attractive foods with difficult textures.
Beside hardness and viscosity, food structural complexity can be also used to increase the swallowing time in elderlies and this insight might be used to design future food offered to the elderly population, which are at risk of swallowing disorder. Furthermore, dental status and bite force of elderly subjects are determining eating capability parameters to design optimised food-texture.
Also investigated was whether ageing influenced sensory capacities in complex food products. Discrimination capacities of young adult and autonomous elderlies were comparable; however, discrimination performances decrease in the older dependent elderly group, who are living in nursing homes.
Sweet apple purees were preferred over sour ones, whichever the level of dependency. However the sweetest apple puree (sugar level: 280 g/kg) was differently appreciated: it was the preferred product for the dependant elderlies while it split the population of autonomous elderlies in two, being cited by them equally as the most liked and the most disliked product.
Sensory discrimination was not impaired in autonomous elderlies, but was lower in dependant elderlies, which was associated with a preference for sweet products. Food products aimed at autonomous elderlies therefore should not require specific taste formulation, while those for dependant elderlies must be adapted.
The nutritional needs were also taken into account: the existing recommendations for daily allowances across Europe were synthetised and used to give aims in amounts per portion. Averages for recommended nutrient concentrations were calculated.
All these recommendations, as well as benchmarking and the collective experience and creativity of the consortium, were used to imagine product concepts. Out of more than 30 product concepts, eight products concepts have been further designed and tested. Most of the products were based on apple (fruit) or carrot (vegetable) as they are among the well-accepted fruits and vegetables, and are available throughout the year for trials.
Five products concepts are based on fruit raw materials (enriched apple puree, healthy confectionery, apple pieces with watermelon texture, apple dessert and smoothie) and three products concepts (carrot puree, culinary aids, concentrated soup) are based on vegetables. The products were enriched either in proteins (apple puree, carrot puree, culinary aids, concentrated soups) or in a vitamin and mineral supplement (healthy confectionary, apple pieces, apple dessert and smoothie).
Innovative processes (high pressure and ohmic heating, new tubular pasteurisation concept) were tested for the stabilisation. For each concept, various formulations have been proposed and 19 selected products (4 concentrated soups, 5 culinary aids, 3 carrot purées, 3 apple dessert and 4 apple based smoothies) have been produced and tested.
Sensory evaluation by an expert panel measured the impact of fortification of the foods with proteins and the impact of processing methods. Addition of proteins in the prototype foods had a major impact on sensory properties and was accepted only in some recipes. In contrast, food processing method had little impact. Among the proteins added, pea protein was the most digestible, in both carrot and apple purée. Processing methods and re-heating increased digestibility.
Temperature And pH Of Foods
Impact of temperatures (cold and warm) and pH relevant to the food composition, food storage and food re-heating conditions, on nutritional value and microbial safety were studied in model solution and in real foods.
Microbial safety was assessed using the spore-forming pathogen B. cereus, in presence and absence of oxygen, in conditions of storage (8-10 deg C), in presence or absence of oxygen, and in conditions or reheating. Foodborne pathogens that could grow during storage of foods are very heat sensitive and easy to kill during food re-heating. However, some strains produce a very heat-resistant toxin (cereulide) and it is still being investigated if they can produce during cold storage.
For vitamins, the focus was on vitamin C as a reporter vitamin and folates. Remarkable differences were noted for vitamin C degradation between model solutions and the actual food products, with better stability in the food products, probably due to limited oxygen availability. This concurred with a meta-analysis, which highlighted a limited impact of processing on the nutritional composition of fruit and vegetable products, notably ascorbic acid, carotenoids and polyphenols. Folate degradation depended of the vitamers and in real food, the most heat sensitive vitamer could be protected by vitamin C.
Environmental and cost performance of the foods will be mostly affected by the conditions of food supply in nursing homes, or at elderlies’ home, and by the mode of storage. The packaging impacts in general are strongly dependent on the product as they vary as a function of the packaging type and quantity.
The most important conclusion is that food transportation is much more optimised for elderly at nursing homes than that for elderly at private homes. Considering the impacts on climate change, if the distance from centralised kitchen to private homes is long, it is preferable for elders at private homes to go to supermarket to buy the ready meal and cook it at home. For elderly at nursing homes, in term of both impacts on climate change and life cycle costs, it is always preferable to deliver the food directly from producers (or through intermediates) to nursing homes and cook it on site.
Evaluation of acceptance of products by seniors dependent for their food preparation, i.e. receiving meals-on-wheels or living in nursing homes, is currently underway.