Fruit puree as a semi-finished confectionery manufacture
Fruits and berries, intended for the preparation of semi-finished products of marmalado-pastille production, are pre-wiped, i.e. they are mashed in order to free the flesh of fruits and berries from inedible parts (peduncles, seeds, seed box, stiff veins, bones) fruit and berry puree are more transportable than whole fruits and berries. Puree is a semi-finished product, convenient for mixing with sugar and other components of the recipe, it is suitable for cooking, churning and for the formation of gelatine with sugar.
One of the most common semi-finished products of confectionery production is apple puree, as it has a good gel-forming ability.
Different varieties of apples have different value for confectionery production. For the development of apple puree mainly winter varieties of apples are used. The main features that determine the technical dignity of apples in terms of puree production are as follows:
a) apples should be removable standard, characterized by a dense structure of the pulp, good keeping quality (the ability to ripen slowly after removal from the tree). Such apples are usually well resistant to the development of diseases and pest infestation, which gives them stability in storage and transportation;
b) apples must have a good jelly-forming ability, which depends not only on the amount of pectin, but also on the quality of the latter, as well as on the ratio between the content of pectin, acid and sugar;
c) the taste and aroma of the apples must be well defined;
d) large and medium sized apples should prevail. Apples that are smaller than 6 cm in diameter are considered small. Small varieties of apples are unprofitable for processing into mashed potatoes due to a large percentage of waste during rubbing;
e) the weak coloring of apples is the most desirable, since in the production of confectionery fruit and berry semi-finished products, the light background of mashed potatoes is appreciated, making it possible to sum up any tone when tinting products.
In this sense, the “Antonovka” variety growing in Ukraine is very valuable in this sense.
In recent years, wild apples have been widely used to produce applesauce. With its small size, the presence of astringency in taste and strong coloring, our wild apples have a high gelatinous ability. According to VKNII , the best in this respect are wild apples from the southern regions of Ukraine.
Puree apples that meet these requirements are usually used to produce marmalade, pastilles. Puree the remaining apples are mainly for the manufacture of fillings, and podvarok jam.
Storage and transportation of apples in production
For storage of 3 — 4-day stock of apples in summer and autumn time light canopies are used to protect apples from rain and direct sunlight. The seasonal stock of winter apples must be stored (during the 1 — 1,5 of the winter months) in warehouses isolated from the outside temperature.
The size of the storage area for apples delivered in boxes is determined on the basis of the rate of loading of boxes to a height of 1,4 — 1,5, which corresponds to 0,7 tons of apples per 1 m2 working area of the warehouse. If portable stacker lifts are used for stacking boxes, stacks can be made somewhat higher and the load on 1 m can be increased accordingly.2. For the aisles and for the work on the opening of the boxes, an increase in the storage area by 25 — 30% is envisaged.
When apples are folded at harvesting points located directly in the growing areas of apples, apples can be stored for a short time (no more than 3 — 6 days) in bulk with low shoulders (not higher than 0,6 g), with grate ventilation ducts in the piles and subject to constant temperature monitoring collar. Under these conditions, the load on 1 m2 The working area of the warehouse is 0,25— 0,3 t apples.
In the cold season it is necessary to insulate the shoulders (straw mats, etc.) to prevent the apples from freezing. If the apples are frozen in transit, they should be stored in the cold and not allowed to thaw them before being put into production.
Packed in boxes, apples are released from the container as they are fed into production, which is carried out by various types of conveyors. For the continuous movement of apples horizontally used conventional belt conveyors.
In practice, hydraulic conveyors, such as those used in sugar factories for transporting beets from hardwood fields to the  plant, have justified themselves well for this purpose.
The hydraulic conveyor is a gutter made of steel, concrete, wood (tarred), brick (covered with cement) and laid slightly below the level of the floor of the warehouse. The chute should have a slope that provides water and apples with a speed of approximately 1 m / s (the slope is about 10 — 20 mm on 1 linear meters of the chute length). When cornering, the slope increases. Apples are evenly pushed into the chute, in which they are fused by the flow of water in the right direction to the required distance. In the course of the movement of apples in certain parts of the gutter or its branches, traps are set for heavy impurities (stones, etc.). These conveyors create additional convenience in the sense that they provide for the removal of accidentally solid bodies from apples, as well as partial washing of apples from dirt. Water consumption for conveyors of this type with a threefold change during the day is 400 — 500% by weight of apples. Significant savings in water consumption can be achieved when using for fusing apples through the conveyor of water drained from an apple lock.
To move the apples from the bottom up, ordinary straight or inclined bucket elevators are used (fig. 1). For convenience of filling the buckets, the base of the elevator is mounted in a special pit.
Fig. 1. Bucket elevator for apples.
Water poured into the 1 pit changes periodically. Apples float in the water, which makes it easier to grab them with buckets elevator. For dripping water trapped with apples, 2 buckets of the Elevator are made perforated.
For the quantitative determination of apples coming from one production site to another, set the automatic scales.
Sort and wash apples
The purpose of sorting apples is to remove unsuitable fruits for production (rotten, moldy, heavily affected by pests), divide apples by degree of ripeness and color, by defects (spots, bruises, etc.) and by size.
The selection of apples according to the degree of maturity and color is important, since the fruits of unequal maturity require different processing modes (softer ripe apples get wet and stew faster than solid, unripe fruits).
Sorting apples by size is also an important prerequisite for uniform processing them when they are locked and filled.
Fig. 2. Fan sink for fruit, berries and vegetables.
Belt conveyors are used to sort apples by quality, maturity and color. The sorting and culling of apples are done on a conveyor, the speed of which is about 0,2 m / s.
To sort apples, as well as other round-shaped fruits, they use special machines equipped with a set of shaking removable sieves with round holes of the required size.
The sorted fruits are automatically discharged from the corresponding sieves into separate gutters.
Sorting apples by size is sometimes combined with sorting them by quality on the above conveyors.
After sorting the apples are sent to the sink. Careful washing of apples with water is necessary in order to wash them from various contaminants adhering to the surface. The smallest hit of sand from apples in mashed potatoes causes an unpleasant feeling of crunch on the teeth, making mashed potatoes unsuitable for use in the confectionery industry. When washing, apples are freed from a significant part of microorganisms present on their surface, as well as from residues of poisonous insecticides used for spraying trees in order to control pests.
Among the various designs of washing machines used in the practice of processing fruits, berries and vegetables, it is necessary to indicate a fan sink adopted in the canning industry (Fig. 2).
It consists of the 1 bath, the 2 conveyor, the 3 shower device, the 4 fan and a bubbler for blowing air and the 5 sump for draining spent water.
The conveyor has two horizontal and one inclined section. The lower horizontal section is under water in the bathtub, and the upper horizontal section can be used to inspect the washed apples.
The air blown by the fan enters the tubes of the bubbler located under the working branch of the conveyor, causing turbulent movement of water in the bath, which promotes intensive washing of the apples without damaging them. Passing through the upper part of the conveyor under the shower, the apples are additionally washed.
These sinks are good for apples and especially for soft fruits and berries.
For small production, a drum (rotary) washer is used, designed for round hard fruits (fig. 3). It is a trough with a planetary or perforated drum rotating in it. Water is poured into the trough and, as it is polluted, it goes down through the bottom drain. Inside the drum is a pipe for splashing water. The guide vanes located along the helix are attached to the inner surface of the drum. In addition, the drum is installed with a slight bias towards the movement of apples. Acting from one end of the drum, the apples receive a rotational-translational motion and, washed in water, exit from the other end. The energetic washing of apples in these washers is ensured by alternately rotating the drum in both directions. The drum is powered in such a way that the apples fill from 73 to 7g of its volume. More polluted apples are loaded into the drum in a minimum quantity so that they are better washed. The productivity of these machines for apples about 5 t / h, water consumption up to 5000 l / h.
The disadvantage of drum-washing is that which takes place in partial damage apples.
Water consumed for washing of apples, the quality of your must meet the requirements for drinking water.
The locking of apples in cold water before a spit (about 24 hour) was used before at fruit-processing enterprises. From practice it is known that after preliminary locking the apple darkens less in the process of curing, than without a lock, and the puree in the first case turns out to be lighter.
In recent years, the locking of apples before the scar in most large enterprises has not been used in connection with. because its role and significance seemed controversial. However, studies by VKNII  have shown that pre-locking fresh apples in cold water helps to preserve the vitamin C of these apples; with apple sharps after locking, vitamin C loss is reduced in 1,5 — 3 times against the loss of shash of unroasted apples. At the same time improves the color of the finished mashed potatoes.
The main influence of the lock is that fresh apples in water (or in any solution) receive significantly less oxygen from the outside than fruits in air. Under these conditions, the respiration of the fruit develops in large part due to the oxygen contained in the tissue of the fruit itself. As a result of intramolecular respiration, the amount of free oxygen in the tissue is reduced and conditions of partial anaerobiosis inside the fruit are created, followed by a decrease in the oxidation of vitamin C, as well as tannins.
According to some assumptions, when locking, part of tannins are removed, which cause bitterness and darkening of mashed potatoes. This effect of the lock is possible as a result of chemical interaction between the tannins of an apple with calcium salts of water. The result of the lock in this respect will depend on the chemical composition of the water going to the lock.
The apples are locked in the continuation of the 8 — 24 hour. The duration of the lock should be adjusted depending on the variety, size and degree of maturity of the apples, and the temperature of the water going to the lock. Hard varieties of apples, unripe, large apples require more time to lock. Soaking in warm water is faster than in cold.
Available research data show that when locking whole intact apples in cold water, no noticeable transition of apple extractive substances into water is observed. This is due to the fact that the peel of a fresh apple has the ability to pass water and at the same time is impermeable or not permeable to the extractive substances of the apple.
Pre-lock is eliminated when working with fumigated apples (apples are processed raw with sulphurous anhydride). Sulfurous anhydride has a similar effect on apples in the sense of softening the pulp and bleaching it.
Apple lock is produced in wooden iron or concrete vats. They must be equipped with devices for feeding water for its descent, as well as drain doors for the withdrawal of mud sediment. For mechanical unloading of apples from vats after a lock, there are devices similar to those found in elevator washers.
For calculations of the capacity of the urinal vats, the specific volume of fresh apples to be filled can be taken equal to 2,0.