The UK diet is high in fat, particularly saturated fat, e.g. in 1992 over 40% of all energy intake was derived from fat, with over 15% coming from saturated fat alone [1
]. The European Economic Community (EEC) nutrition policy goal suggested that only 20–30% of energy should be derived from fat [2
]. There is considerable epidemiological evidence that nutritional intake is related to the risk of coronary heart disease (CHD) [3
]. To reduce the incidence of CHD the department of Health has recommended that the proportions of energy derived from total fat should be reduced to 35%, and from saturated fat to 10% [1
Also, the replacement of saturated or trans-unsaturated fat with unhydrogenated unsaturated fats is associated with larger reductions in risk factors associated with CHD than replacement by carbohydrate [5
Other dietary changes considered helpful in the fight against coronary heart disease include consumption of a high fibre diet [6
], reduction of salt and sugar intake [7
]. In a study conducted by Pietinen et al
] the mean intake of soluble fibre in the diet was 5.4 g.day-1
compared to 18.9 g.day-1
for insoluble fibre. They reported that an increase in daily soluble fibre by 3 g reduced the risk of coronary death by 27%. Dietary sodium reduction has been recommended to reduce hypertension and cardiovascular disease mortality and morbidity [9
]. Large amounts of sucrose, or other refined carbohydrate, cause an increase in lipid triglyceride, an increase not associated with complex-starch intake [8
]. Biscuits are a popular food eaten by both children and adults; however, they are typically high in the materials (fat and sugar) that make them "unhealthy". In the manufacture of biscuit dough, it is traditional to use fat which is semi-solid at room temperature e.g. palm oil which contains 50% saturated fatty acids. In addition, the biscuit market is dominated by short dough biscuits having fat levels in excess of 20% [10
]. Biscuits are therefore an obvious choice when consumers are asked to reduce their total fat intake. The concluding paragraph of the Diet and Heart Disease report [11
] states that high fat bakery products should be reduced in the diet. In addition, biscuits have previously been highlighted in a report by Willet et al
] as being significantly associated with an increased risk of CHD.
The development of a commercially viable biscuit attractive to children and adults that will have a significant reduction in fat and sugar, with fewer calories and contain nutrients designed to reduce the risk of coronary heart disease is highly desirable.
The purpose of this study is to describe the development of a healthy biscuit (functional food) with low moisture, long shelf life that has commercial viability, has had sodium chloride reduced and pre-biotic fibre, B6, B12, folic acid and vitamin C added.
A food can be regarded as functional if it is satisfactorily demonstrated to beneficially affect one or more target functions in the body, beyond adequate nutrition, in a way that improves health and well being or reduces the risk of Disease [13
]. The term functional food was first used in Japan [15
], and Japan has been active in the development of this type of product since the early 1980's.
Research to date has focused on several factors that contribute to the health status of individuals. This study has focused attention on the modification of a standard biscuit by the addition of vitamin B6, vitamin B12, Folic Acid, Vitamin C and Prebiotic fibre, while reducing salt and sugar, thereby converting a traditional food product into a functional one.
Vitamin C (ascorbic acid)
Ascorbic acid (vitamin C, 2,3-didehydro-L-threo-hexonic acid-g-lactone) is an acid derivative of a 6-carbon sugar. The presence of the "diol" grouping at carbons 2- and 3- enables the vitamin to act as a powerful reducing agent. It is evident that subjects with acute myocardial infarction have lower plasma vitamin C than control Subjects [16
]. Although there is no universally accepted recommended daily intake of vitamin C, the World Health Organisation recommends a daily intake of 30 mg, whereas in the UK the RDA is 60 mg1
Prebiotic fibre (fructo-oligosaccharide)
A prebiotic is defined as a non digestible food ingredient that beneficially affects the host by selectively stimulating the growth and/or the activity of one or a number of bacteria in the colon that have the potential to improve health [20
]. Prebiotics, most often referred to as non-digestible oligosaccharides, are extracted from natural sources, e.g. Inulin and oligofructose, or synthesised from disaccharides. Actilight®
, the prebiotic that was used in this study was obtained from sugar beet comprising of one molecule of glucose linked to two, three or four molecules of fructose. Its use in the final product formulation contributed to the dough characteristics and the organoleptic properties of the biscuit.
A number of studies have shown biochemical signs of deficiency or inadequacy of vitamin B6
in around 10–20% of apparently healthy people [22
]. This may be a factor in the development of atherosclerosis, a result of impaired metabolism of methionine and raised circulating levels of homocysteine [22
]. Reference nutrient intakes (RNIs) are based on 15–16 μg.g-1
of protein per day. At average intakes of 100 g protein per day this gives an RNI of 1.5–1.6 mg of vitamin B6.
Average intakes in Britain are between 20–30 μg.g-1
The current RNI for vitamin B12
is 1.5 μg.
for males and females 15 to 50+ years [1
]. The addition of Vitamin B12
in the modified biscuit follows the recommendations of several authors [22
], who observed elevated homocysteine concentrations as a result of impaired vitamin B12
status which has been implicated as a cause of premature cardiovascular disease.
Folate (folic acid)
Folic acid is involved in a number of single carbon transfer reactions, e.g. in the synthesis of methionine [25
], the metabolism of which results in the production of homocysteine as an intermediate product. Normal levels of homocysteine for men are around 8–12 micromoles per litre (μmol.l-1
) and for women normal levels are 6–10 μmol.l-1
]. High blood homocysteine is thought to be an independent risk factor for CHD [26
]. The conventional view is that as an individual regresses into a negative folate balance, there is a reduction in plasma and tissue concentrations. This would be followed by small and eventually large increases in homocysteine levels [30
Since moderate reduction in folate status results in elevated plasma homocysteine, a relationship between folate status and risk of cardiovascular disease has been established [29
]. Whilst supplements are suitable for those aware of the potential benefit, even following significant publicity, it's clear that only a small minority of people, especially in the poorer socio-economic sector where the risks may be greater, will take beneficial supplements on a regular basis [32
]. This has resulted in suggestions that the diet should be fortified with folic acid, and in the USA it is now policy that flour is required by law to be fortified with folic acid.