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Final Report Summary - SOFBJ_PRODHUMHEALTH (Sugar and Oxalate Free Beetroot Juice: Production and Assessment of its Human Health Benefits)

‘Let food be thy medicine, and medicine be thy food’, an aged quote from Hippocrates, the ancient Greek physician and “Father of Modern Medicine” that could certainly be applied to a very modern trend in food culture. It could represent a contemporary strategy to revolutionise healthcare and stimulate an increasing synergy between the food we eat and overall health and wellbeing. Beetroot, or Beta vulgaris L., a tuber and member of the Chenopodiaceae family of flowering plants has gained recognition as a ‘functional food’ in recent times, but which has a history of medicinal usage dating back to Roman times. Abundant in folic acid, vitamins A and B6, magnesium, selenium, zinc as well as phytochemical compounds; ascorbic acid, carotenoids, phenolic acids and flavonoids. Beetroot is also one of the few vegetables to be a source of betalains; pigments with potent anti-inflammatory and antioxidant capabilities, implicated as having therapeutic potential for the treatment of conditions characterised by chronic inflammation and oxidative stress. Beetroot is particularly rich in highly bioavailable inorganic nitrate, containing on average upwards of 250mg per 100g. The therapeutic potential of inorganic nitrate supplementation is now widely recognised to play a significant role in the maintenance of general health, as well as aiding athletic performance. Inorganic nitrate can be reduced to nitrite upon ingestion, it is extracted from the blood, after absorption across the upper intestine, via salivary glands. There, in the oral cavity, inorganic oxide is reduced to nitrite due to the action of commensal bacteria. Nitrite then enters the circulation via saliva upon swallowing; nitrate reductases then act to convert nitrite to nitric oxide (NO) which acts as a vasoprotective agent. Inadequate diet can result in hypertension, due to insufficient dietary sources of inorganic nitrate. NO, one of the smallest biologically active messenger molecules, has an important role to play in the maintenance of cardiovascular, immune system and central nervous system function. For example, NO is involved in the adjustment of regional cerebral blood flow, the modulation of synaptic plasticity and the regulation of cell respiration. Nitrate consumption has been linked to a variety of beneficial health effects, primarily in relation to blood flow, circulation and mood and cognition.

In contrast to its health benefits, beetroot contain high content of oxalales, about 800-1000 mg oxalic acid oxalic acid per 100 mL beetroot juice and diets with increased consumption of oxalate could cause adverse effects to the consumer. Oxalates become present in humans through natural endogenous production, along with dietary sources. It is digested and absorbed in the intestinal tract, whereby oxalate specific microbiota breakdown the substance or calcium is bound to it, thus creating calcium oxalate (CaOxa). Although low levels of oxalate within the body are safe, larger levels lead to many health problems. Primarily, oxalate is largely responsible for the production of kidney stones, with around 80% of these being formed via CaOxa. When calcium binds to oxalate, hyperoxaluria becomes present and CaOxa crystals are formed, which become trapped in the urinary tract causing kidney stones and their related negative health outcomes. Moreover, as oxalate frequently combines with metal cations, it may inhibit absorption of essential metals required for healthy human function such as magnesium and calcium; as such it is often recommended that oxalate levels in the diet are reduced for several disease states such as gout and rheumatoid arthritis. The acute oxalate nephropathy has been reported as well in case of Star fruit which is popular in many tropical countries and contains high levels of oxalate (1.5-2.0 g/ 100 mL of juice ). The formation of large amounts of calcium oxalate crystals in the body may produce hypocalcemia as well as renal dysfunction, renal calculi, and electrolyte imbalance. The deposition of calcium oxalate crystals in the myocardium of patients with renal failure may occur without the presence of oxalate poisoning. Pathological changes associated with fatal oxalate ingestions include corrosive effects on the gastrointestinal tract, cloudy swelling and hyalin degeneration of the renal tubules, glomerulosclerosis, and birefringent crystals in vascular walls throughout the body. A normal dietary intake of oxalate is estimated to be in the range of 50–200 mg daily. Therefore the frequent consumption of beetroot and beetroot juice products or indeed any other high oxalate containing vegetable juice in their current high oxalate containing form, is very likely to have strong negative effects on consumer’s health on the long term.

As well as their high oxalate content, beetroots also contain significant amount of sugars (70-110g/L) something that makes beetroot to be more similar with fruits (60-150g/L) than other vegetables (3-40g/L). Consequently, the significant sugar content of beetroot juice could prevent consumption of the juice by segments of the population such as diabetics whom mostly need increased beetroot juice consumption for reduction of arterial stiffness and blood pressure. In a 2012 market report by Mintel, natural fruit juices are perceived by consumers as containing too much sugar. In a modern lifestyle low on manual work and exercise it is understandable that sugars are perceived by consumers as unnecessary caloric value. Furthermore on March 2015 WHO has issued a “Free Sugars” intake guideline for adults and children and according to this intake of free sugars should not exceed 10% of total energy intake with 5% considered a healthier practise. According to WHO “Free Sugars” refer to monosaccharides (such as glucose, fructose) and disaccharides (such as sucrose or table sugar) added to foods and drinks by the manufacturer, cook or consumer, and sugars naturally present in honey, syrups, fruit juices and fruit juice concentrates. Consequently, frequent consumption of beetroot or other fruit juices is not considered a healthy habit anymore which is a great pity since fruit juices are an excellent source of healthy compounds that can be very easily consumed from people.

In line with the earlier mentioned findings the IEF project was aiming to establish the feasibility for the generation of a healthier beetroot juice using mild processing as well as comparing its human health benefits with conventional beetroot juices. Specifically the research objectives of the project has been to
1. Develop a mild process that would produce a healthier version of beetroot juice.
2. Generate the healthier beetroot juice at food grade status and in sufficient quantities to conduct human trials.
3. Assess human health benefits of the healthier beetroot juice in 2 health domains. a) Cerebral blood flow parameters, cognition and mood; b) Blood pressure and Vascular function.

Within the life span of the project a number of possible mild processes were investigated. As a result of the investigations an appropriate mild process has been discovered that allows to generate a healthier juice composition from beetroot or indeed any other fruit or vegetable juice. In accordance to the project objectives a draft patent filing has been generated to protect the arising intellectual property rights of Northumbria University for the discovered healthy juice composition together with the corresponding mild process. To promote exploitation of the result for the benefits of the food industry and consumers alike, discussions with industrial partners for scale-up of the technological breakthrough are ongoing. These discussions have been significantly augmented due to the existence of the patent draft, the food grade samples of the invention and the overall level of technological maturity of the project all of which have been accomplished as a result to FP7-PEOPLE-IEF funding.
Healthier composition Beetroot juice has been produced at food grade status and in sufficient quantities to conduct human trials. The assessment of healthier beetroot juice against the conventional one has taken place only in the domain of cerebral blood flow parameters, cognition and mood. Our results have revealed no significant differences in the attributes studied between the healthier and conventional beetroot. Unfortunately there was not possible to execute the trial for the assessment of blood pressure and vascular function within the life span of the project.
The project has generated a range of disseminated scientific outcomes summarised as contributions to: one published article in Green Chemistry (IF 8.5) a Royal Society of Chemistry journal; four oral and two posters in international conferences and EU/RCUK sponsored workshops. Further to this one draft patent filling and three manuscripts under preparation are yet to be submitted within 2017.

It is inherent to Marie Curie fellowships to seek to diversify/broaden the competencies of the research fellow and constitute a significant milestone in their career developments assisting researchers in attaining and/or strengthening a leading independent position. To accomplish this in our project a career development plan with specific training objectives has been planned and executed. Key driver of the development plan has been the fact that the project by itself constituted an excellent training opportunity for the fellow helping him to expand his skills in areas that he has not had the opportunity to acquire training earlier in his career. In particular the present proposal represented a genuine multidisciplinary project linking process design (chemical separations) to food manufacturing (Food Engineering) and assessment of human health benefits (Nutrition). The execution of the fellowship resulted in a significant uplifting in the research skills of the fellow. He became experienced with work on multidisciplinary project teams for designing a food compatible process, food raw material processing and looking into the products’ results on substantiating any health benefits, demonstrating thus the biological activity of the generated fractions. In summation the fellow indeed acquired a range of diversified professional skills that are not often possessed by a single individual. Indicative of the successful completion of the training programme of the IEF has been that the fellow as soon as he concluded his MC fellowship he was immediately appointed as Lecturer in Bioprocess Engineering at Lancaster University, UK - one of the leading universities in engineering in UK and globally.

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