8 Dried fruit and nuts Considerable variety in both flavour, appearance and texture can be achieved in biscuits by using dried fruits and nuts. As biscuits are mostly small and thin products the fruit and nuts have to be either small themselves or cut into small pieces. Generally, nuts do not have enough flavour to make a distinctive contribution to the acceptability of a biscuit unless they are used in large amounts. As both nuts and dried fruits are expensive ingredients it is normal to use them in such a way that they are obvious to the consumer, for example, by arranging that at least some of the nut pieces are applied to the surface of the dough piece as decoration. The user of dried fruits and nuts must be concerned with: 1 flavour of the product 2 size and appearance 3 cleanliness in terms of dust, dirt, stones and other adventitious matter and 4 level of infestation or deterioration which has developed after harvesting and in storage. The countries and areas of origin of dried fruits and nuts, and the fact that they are produced very often by unsophisticated people, may lead to many problems with quality. Insufficient care may be taken to protect the materials from dirt and dust, and the nature of the product and climate mean that insect infestation is prevalent. However, great advances have been made in improving the hygiene associated with drying and storage of dried fruit. It is important to realise that in order to change the practices of some of these simple farmers they must be shown and told again and again for in most cases they have no idea of the stringent requirements for food in the factories and countries where their produce is sold. 52 Dried fruit and nub 53 8.1 Dried grapes 8.1.1 Currants Currants are small black seedless tasty and nutritious grapes grown in Greece. Currants have found particular value in biscuits because they can be obtained as good quality small clean seedless fruit and their strong flavour gives them a particular advantage. After drying, either in the sun or in the shade, the fruit is separated from the stems and stalks by a method of threshing, winnowing and sieving but the currants are damaged as little as possible. The dried fruit is either sold directly or kept in store on solid floors usually in bulk or in sacks or boxes. Before export the fruit is further screened to remove stalks, stones and any other large unwanted pieces and is washed to remove dirt. The fruit is graded with sieves to give pinheads, smalls, mediums and elephants, in ascending size order. The pinheads are of little value because it is difficult to separate effectively all the stones. At the other extreme the elephants tend to be large fruits with pips (or seeds) in them which make them less attractive to eat. Thus, only the smalls and mediums are of value to biscuit makers. As a rough guide there should be about 500 berries per lOOg for mediums and 900 berries per lOOg for smalls. This means that currants are available as a much smaller fruit than any raisin types. The packers claim to have a moisture content at packing of around 16% but in practice values nearer to 20% are more common. Currants are packed into 12.5 kg cardboard boxes for shipment. These boxes may or may not be polyethylene lined. The names on the boxes vary considerably and are not a little confusing. In addition to the type and grade of currant another, less descriptive, name often appears. Each packer has his own names and often the trader or agent in the country of re-sale uses his name. Thus, a name may not be particular to a particular packer or conversely one packer’s name may be sold through many different agents. From the point of view of the user, the packer is the important person because well cleaned and graded fruit can usually be related to a fastidious well equipped packing factory. Insect infestation is a problem in currants, especially those which have been laid in store for a season. It has become standard practice to fumigate with methyl bromide gas, under slight vacuum, after packing and immediately before shipment. When the fruit is to be used in the biscuit factory it is advisable to re-wash a few hours beforehand. This removes more of the dust and 54 Biscuit, cookie and cracker manufacturing manuals dirt and also breaks up fruit which has become compacted during transportation. Finds of stones, stalks etc. are very unpleasant in biscuits and if necessary the fruit should be checked at the time of re- washing. No machine has yet been made that can completely remove all this rubbish from currants so picking by hand on white tables or conveyors is advisable. This work is boring and requires much concentration. It is strongly recommended that the best and cleanest fruit is purchased rather than reliance being placed on screening in the biscuit factory. Specialist companies operate a cleaning service for dried fruit usually in conjunction with a packaging business for the domestic market. Their charges are such that it is usually more economical to buy a better grade from Greece. Also repackaged fruit will be softer and more susceptible to damage than the dry fruit from Greece. Formerly, dressing the fruit with 0.5% tasteless mineral oil reduced aggregation of the washed fruit. The use of mineral oil in food has now been prohibited in many countries and the mineral dressing oil has been replaced with special high stability vegetable oils like Durkex 500. As the fruit is washed it picks up about 2% moisture. This fact should be considered when recently washed fruit is purchased. 8.1.2 Thompson seedless raisins and sultanas Thompson seedless raisins, unlike currants which are peculiar to Greece, can be obtained from a number of different countries, principal of which are USA, Turkey, Chile, South Africa and Iran. The USA is the largest producer and there is no doubt that the quality of their fruit is very good. Most US raisins are ‘naturals’, that is, sun dried and processed without chemical treatment, giving a dark coloured fruit. There is a small proportion of sulphur dioxide bleached grapes which are artificially dried and these produce golden raisins which are like sultanas from other countries. Smyrna sultanas are directly related to Thompson seedless raisins and represent a significant and very ancient trade from Turkey and Greece (principally the island of Crete). Australia and Iran are also significant producers and exporters of sultanas. Both raisins and sultanas are always larger and more fleshy than currants and therefore less suitable for biscuit making. When a fleshy fruit is dried out during baking it becomes tough and leathery, perhaps even hard and bitter if on the surface of the product. Dried fruit and nuts 55 Traditionally bunches of sultana grapes are dipped in a solution of potassium carbonate emulsified with a little olive oil before being laid on a compacted earth bed to be dried in the sun. This treatment removes the bloom on the grape surface, softens the skin and hastens the drying. The sultana is dried till it starts to darken, a pale sultana is prized so overdrying is avoided. The dipping prior to drying also reduces the tendency to darken, hence the difference from Thompson seedless ‘naturals’. On arrival at the packing factory the fruit is washed, spin dried, picked and graded. A high proportion is also bleached with sulphur dioxide gas. This has some significance for the biscuit maker as traces of this reducing agent may have an effect on the biscuit dough. Grading of sultanas and Thompson seedless raisins is based on screen size, colour and counts of defects and foreign matter. 8.2 Other dried fruits used in biscuits 8.2.1 Dates Dates are sometimes used in the form of paste, in a similar way to fig paste (see later) but also as chopped pieces of fruit. The paste is higher in sugars and lower in fibre than figs. The flavour is less distinct and mostly ‘sweet’. Chopped dates may be used in wire cut doughs but it is often difficult to cut the pieces either small enough or of uniform size. Chopped pieces of date must be rolled in rice flour or something similar to prevent them sticking together and forming lumps. 8.2.2 Glaci cherries Glaci cherries are produced principally in France. They are strongly dyed red and are sold in a heavy sugar syrup. It is necessary to wash away the syrup before using these cherries in a dough and this represents a large loss in weight. The cherries add only coloured pieces to the dough and are an expensive ingredient. 8.2.3 Crystallised or candied ginger Crystallised or candied ginger is increasing being used in quality biscuits. Ginger flavour has for long been regarded as a cover flavour 56 Biscuit, cookie and cracker manufacturing manuals for an inferior product but ginger is in fact a popular flavour and the use of chewy pieces of ginger together with ground ginger, and some paprika to increase the heat of the flavour, can produce a good cookie. 8.2.4 Crystallised or candied peel Crystallised or candied peel is usually orange or lemon. It serves principally to add colourful interest and some texture to the biscuit without contributing to the flavour. There is a strong tendency for the peel to become hard or at least tough in the baked biscuit. 8.2.5 Fruit pastes and syrups Various fruits like raisins, prunes, dates and figs are processed to form pastes and syrups (concentrates). The syrups are water extracts concentrated to 70% solids under vacuum and the pastes are macerates to about 75% solids. Pastes have been used for fillings of biscuits like fig bar (Fig Newtons) and all pastes are useful for dough flavours. Obviously the manufacturer of a paste can conceal the use of substandard fruit so care should be taken to select the supplier well. The point of considerable importance in pastes is cleanliness of the fruit prior to processing. The presence of sandy gritty particles is particularly unpleasant as are pieces of pip or stones (prunes and dates). Storage of pastes is more critical than for dried whole fruit since moisture pick-up will cause extreme stickiness. Drying out will cause the mass to become very hard. It is wise to store at a temperature between 15- 21°C at a relative humidity of about 60%. Pastes are usually packed in polythene lined drums of 501b (22.7 kg) ex USA and polythene lined boxes of 12.5 kg from other countries. The pastes are dark or very dark and will darken even more during storage. There is a tendency for fig paste to develop a strong unpleasant taste on aging, so only paste made from the current season’s crop should be used. It is common for pastes, particularly prune paste, to contain preservative. This is usually sorbic acid which is permitted to a level of 1000 ppm (0.1%). Pastes are a particularly useful ingredient for flavouring and as the syrup component in soft cookies. Dried fruit and nuts 57 8.3 Nuts Nuts may be used whole, chopped into coarse pieces or sliced. An exception is coconut where, because of the size of the whole edible part within the nut, after drying (to form copra) it is shredded to a desired size. Nuts, being living seeds, will not store well in damp or humid conditions. When they have been shelled and damaged, either by accident or by chopping or grinding, the enzyme lipase is released which will rapidly result in deterioration by fat rancidity. To prevent this and also to improve the flavour, it is common to roast or deep fry nuts. The heat treatment destroys the enzyme. It is of great importance that pieces of shell are removed from shelled nuts because they are very hard and can cause damage to teeth. The shell must be removed before the nuts are chopped or sliced. There is a growing interest in refined (fine ground) nut paste for biscuit cream fillings and as centres for dual element cookies. 8.3.1 Almonds Almonds are highly prized in biscuits. They may be used as pieces or slices and are usually roasted. The brown skin of the nut is not only bitter but releases enzymes that quickly spoil the nuts if damaged. A technique of blanching and peeling is therefore common for almonds. This involves immersion in hot water which softens and loosens the skin for subsequent easy removal. After the almonds have been peeled, it is much easier to check the soundness of the kernels by their colour. Almond butter may occasionally be used to flavour biscuits. 8.3.2 Brazils Brazil nuts are rarely used for biscuits because of their higher price but their large size makes them suitable for slicing and use as surface decoration. 8.3.3 Cashews Cashew nuts are produced in India, Brazil and East Africa. Their high cost has meant that they have rarely been used in biscuits. 58 Biscuit, cookie and cracker manufacturing manuals 8.3.4 Coconut Coconut in desiccated form is obtained principally from Sri Lanka (formerly Ceylon) and the Philippines. From a hygiene point of view the Philippine product is better, but Ceylonese coconut is considered to have a better flavour. Desiccated coconut is graded according to particle size and shape. For biscuit doughs it is best to use very fine coconut, known as coconut flour. As this tends to lump badly during storage it is best to buy a larger grade (medium or fine) and to mill it immediately prior to use. Roasted or toasted coconut is made, as for other nuts, by dry heating the nut particles. It produces a browned product which has a fine nutty flavour and is said to be easier to digest than the unroasted type * Coconut should have a moisture content maximum of 3% and a fat content minimum of 55%. It is important to check that the bags are sound and dry. Dampened coconut quickly develops mould spoilage which turns it yellow or black. Damp coconut also tends to become rancid, resulting in a soapy taste. Storage under good conditions, about 1&15"C at a relative humidity of 50%, will allow coconut to be kept for many months. 8.3.5 Hazelnuts Hazelnuts (filberts) are the most commonly used nuts in baking. They are particularly popular in European and Mediterranean countries which is where most are grown. Strangely, these nuts are not popular in the USA. 8.3.6 Peanuts All the nuts described here are so far are tree nuts but the peanut, (ground nut) comes from pods formed underground. Peanuts are commonly used in biscuits, particularly in the USA. They may be used as 'halves', to decorate the biscuit surface, or chopped and roasted. In certain cases peanut butter is useful. This is made from milled nuts. There is a growing concern about peanut allergy so products containing peanuts should be very clearly labelled. Dried fruit and nuts 59 8.3.7 Walnuts and pecans Walnuts are by far the most popular nut used for bakery products in the USA. They are available for biscuits as pieces and slices. Walnuts are never roasted before use. Pecans are similar to walnuts but of milder flavour.