Our new subject: researching report

This year we have a new subject which is named Researching Report. In this subject our teacher is Pablo, who's also our Biology teacher. In the first term we had to do a work about the olive trees, their main characteristics, its fruits, the places where they are located in Europe and Spain and also the extraction of the oil with the olive mill. In the second term we had to do some laboratory experiences. We have done soap with oil, we have extracted oil and we have determinated the glucides and the proteins.

It has been very interesting to write about this and to do experiments with olives.

Olive tree main characteristics

OLIVE TREE MAIN CHARACTERISTICS



The olive tree is a tree that belongs to botanical family Oleaceae, and in that family is the only kind with eateable fruit. The pricipal characterisitcs of the olive tree are:

- The leaves are dark for the bundle, with a characteristic sheen due to the existence of a thick cuticle and whitish for the back, simple, of lanceolate form and entire edges. Is a everlasting tree and his leaves are in the habit of living two or three years.

- The blossom is little.

- The trunk is thick and his bark is greyish.

- The fruit is the olive a small ovoid drupe of a very bitter taste, green yellowish color, oily flesh a time they have arrived to the maturity and with a bone that enclosses the seed.

Olive's characteristics

The Olives Anatomy

The olive fruit is boticanically classified as a drupe, it's similar to the peach. Inside the stone has one or two seeds. The olive has got a lot of oil content. They have a black colour and they will hang on the tree for several weeks till they fall off.

Olive's are diffeerent from the other drupes in their chemical composition by having a low concentration of sugars (12%), high oil content (30%) and with a strong taste.

It's component parts are : the epicarp or epidermis, the flesh and the endocarp which has a woody shell with the seeds in it.

The oil content as the general composition of the pulp is highly variable, and it depends on a lot of factors such as climate, soil, culture, systems, pruning, fertilizers, tree treatments and harvesting methods.

Harvest Methods

They are picked while they are still green but they have a full size. Mold is a problem for the fruit between picking and curing.

The different types of methods are:

-The sweep of the ground to pick the olives that fall down.

-You do an extension of nets or canvases around the olive.

-Retail-trode and milking of the tree.

-Pick up of the nets with the olives inside.

-separation of the leaves from the olives.

-The best of these methods is the milking: you can do it by hand or with rackets. The best of these methods is the milking ; you can do it by hand or with rackets. To obtain a high quality of oil, is very important to pick up the olive in the best moment of the ripeness, when the colour of the olive changes.

For ten years, it has been trying the vibrator skill but its emplyment is unlimited for the excessive corpulence of the olive trees.

Types of olives

-The Sicilian Style: It has a medium green colour; they are cured in salt brine and preserved with lactic acid.

-The Gaeta Style: It becomes from Italy, it's cured with dry-salt and then, they are rubbed with oil. They have a black colour and they are wrinkled, but surprisingly mild.

-The Nicoise Style: Its clour is brown to brown-green-black olive and it has the origin in france. It has a small size and it's very tasty.

-The Conservaela Style: Is the most important olive economically. It grows throughout the country from sea level up to altitudes of 600 meters. It has a oval-shaped size and a thin, elastic and resistant skin, and the pulp has a fine, consistent texture.

-The Calamata Style: Its name derives from the region surrounding the town of calamata in the southwest peloponese. This is the second most important variety. They are cylindro-conical, curved, showing a prominent tip at the end. Their skin is thin, elastic and has an intense black colour when it matures.

-The Chaldiki Style: It is wainly cultivated in the chalkiki region of northern Greece. They are more elongated.

Germination of the Olive seeds

To break the dormancy of the olive seeds:

1- Remove the bulb.

2- Excise the endocarb.

3- Put the seeds on a bed of 1 cm of fine moisted perlite and cover the seeds with 1/2 cm of fine granules of perlite.

4- Store the seeds in a glass or a plastic container and put them in the fridge.

5- They start to germinate in 4 weeks.

6- Transfer them into a germinating room and in an appropiate media (20 degrees).

7- In 2 weeks you will see the seeds coming out.

Different Recipes

Olives in Greek Sauce:
It's a mixture of olive oils, vinegar, leeks and salt.
Cream of olives:

For the recipe we need:

-A quarter of pearl onion

-Four Cups of chicken stock

-Two thousand grames of green olives

-Seven thousand grames of purple olives

-Two and a half cups of cream

-Two spoonfuls of oil -Salt and pepper

1- Chop the onion and beat with green olives for 3 minutes. add the chicken stock, the cream and salt and pepper and let it boil for 15 minutes till it reduces.

Preparation of the olives for the table: Cut the olives with a hammer or making cuts with a knife. Put the olives in a container ith clean water. in case of green olives change the water every 10 days. In case of black olives, every 7 days. Finally rinse them and open them with salty water. To leave them rest for 15 days in a fresh place. Finally serve them.

The olive tree in Europe

A 16% of the surface of culture of the olive tree of the world is in Spain. In reference to the world production 26% is from Spain, followed by Italy with 18% and from Greece with 15%.
In Italy, the most part of the production is destined to the production of oil. There, there are only more than 300 people that cultivate olive trees.
About the origin of the olive tree in Europe, the Phoenicians introduced the olive tree in Europe, concretly in Greece. From here it went on to Rome and to all its empire. For them, the olive tree, represented the strength

The olive tree in Spain

It's present in the most part of Spain. It's more important in the provinces of La Rioja, Lleida, Zaragoza, Tarragona, Baleares, Toledo, Ciudad Real, Badajoz, Jaén, Córdoba, Granada, Cádiz, Sevilla and Málaga. Only in Spain there are 260 types of olive trees. Among them they are: Picual: It suposses the 50% of the production in Spain and the 20% all over the world. It prevails in the South of Spain.

Cornicaba: It's the second in importance and third in production. It prevails in the center of Spain in the comunity of Castilla- La Mancha.
Hojiblanca: It suposses the 16% of the andaluz olive tree. It's used for olive and for oil.
Arbequina: it's in the Cataluña's and Aragon's zone. It is cultivated alone and partner to the vineyards.
Lechín of Sevilla: It's in the south of Spain in Andalucia.
Verdial of Badajoz: It extends from Badajoz to Portugal.
Verdial Velez-Málaga: In the south- east of Málaga.
Empeltre: It's common in Aragón, Islas Baleares and Logroño. It is characterized by the excellent quality of its oil.
Pinado: It centers in the south of Spain, especially in Córdoba. It is cultivated for the production of the olives.

Types of olive oil

Virgen olive oil: it can be only be called that if it has been obtained from using entirely mechanical of physical processes. They are either made with one variety of olive or with two or more different types.
Extra virgen olive oil: It has an acidity below 0.8 and is free from all sensory defects.
Olive oil: It has an acidity below 1 and it has a mild aroma, taste and colour.
Pomace oil or orujo: It is made using the solid residue left when th olive oil has been extracted from the fruit.
Virgen olive oil: It has an acidity below 2 and the flavour may have slight organoleptic defects.
Lampant oils: They are virgin oils not suitable for human consuption.

Olive Oil Extraction

It is a process of extracting the oil from the olive drupes to use for food or for other uses.

A drupe is a part of a fruit which has a seed that is surrounded by an outer fleshy part.

The oil in the olive is produced in the mesocrap cells and then it is stored in a particular type of vacuole which is named lipovacuole.
The extraction is a process in which the oil is separated from the other fruit contents, in this case the olive. The separation of the oil from the other oils is by chemical means and the separation of th oil from the solids is by physical means.
Olive oil presses or mills have been around for over 5.000 years or even more. The greeks were the frist people in history to start pressing olives to make oil.
What happens in an olive oil mill.
At frist the olives are harvested from the olive felds. Then the harvested is washed with potable water and the dirt, the leaves and what ever else is removed from the olives.
After that the olives are then placed onto large millstones, where they are crushed. They are left there for about 30 to 40 minutes until the olives have formed some sort of paste.
Then the olive paste that is left after the crushing of the olives is either: Spreaed on fiber disks, which are then stacked on top of each other. Then pressure is applied on the disks, compacting the solid paste and forming a liquid.
Mixed and beat which prepares the paste for separation of the oil from the pomace. Then extraction of the oil is accomplished by applying pressure.
The waste consists of solid and liquid waste. The solid waste is used as fuel, fertilizer, herbicide, animal feed, road construction material, olive bricks and worm breeding material.

Practice 1: Determination of the quantity of water

With these experiments we want to recognize the different chemical components (water, lipids and glucids) of the olive, as much in the pulp as in the seed.



PRACTICE 1: DETERMINATION OF THE QUANTITY OF WATER



All living creatures are made up of a big percentage by water. To lead the percentage of content in water of the olives we'll continue the follow steps:


1. We take three olives, we measure them, we make an incision in them (to evaporate more quickly) and we put them in a recipient to dry them.
- Picture
- Fresh weight: 9.6 g.


2. We place the recipient with the two olives in a stove and we let them during a week to dry them well (to evaporate all the water that they have)
- Picture
- Fresh weight: 3.3 g.
- Therefore, the difference of weight will correspond to the water: 6.3 g.
- Calculate now the percentage of water that olives have:

Practise 2-Determinate glucose reductors

Glucides are the most important substances that the plants obtain the energy that they need to do their vital functions. Between glucides there are sugars and polisacarids (like starch, reserve substances of energy of plants).
In this exercise we are going to find out with chemical methods the sugars of the pulp in an olive.
1- We get an olive, we take off the pulp and we live the stone apart.
2- We cut the pulp in piezes and we put them into a container.
3- We grind it with a morter.
4- We add a bit of water to make the pasta a bit mor fluid.
5- We put the olive pasta in a test tube.
6- With a pipette we put 2 cm3 of Fehling A ina test tube.
7- In that test tube we add other 2 cm3 of Fehling B, we obtain a dark-blue colour.
8- Then, we put this disolution in a test tube where there is the pulp of the grind olive and we mix it.
9- Finally, we warm the mixture with a gas burner.
10- If the mixtur turns to a red colour, it could be because of the glucides reductors, that in this case is the glucose.

Practise 3: Starch determination

As well as the sugars in the plants there are glucides polysaccharides like the starch, the substance that will be obtained from the pulp. That substance is the reserve of a lot of the plants.

1- To obtain a sample to compair with, we will take a potato, that is rich in starch. After chopping the potato by the middle and to cut it, we throw some drops of lugol. That colouring dyes purple the starch.

2- We take now an olive, we take off the pulp and we mince it.

3- When the pulp of the olive is minced, we throw some drops of lugol.

4- Conclusions: we can't see very well the purple colour because the olive pulp is too dark. But it is rich in starch, so it colours.

Practise 4. Determination of proteins and reaction of the biuret

To determine the presence of proteins we will realize two experiments:
Xantoproteinc reaction:

1- Extract some olive seeds chopping the stones.

2- We leave them drying for one week.

3- We take the dry olive seeds and we mince them in a container.

4- Minced we throw them in a test tube and we add 1 cm3 of nitric acid (HNO3) concentrated.

5- We heat the test tube with a lihgter. If there are proteins, they will react with the HNO3 and the sample will become yellow.

Reaction of the biuret
The name of the reaction is bacause of when the proteins get in contact with blond it produces a substance called biuret.

1- We get some dry seeds of olives and we grind them in a container.

2- When they are grind we put them in a test tube and we add 1 cm3 of sodic hidroxide in a 20%. In case that there are proteins, it would produce biuret.

3- Then we add some drops of sulfato cuprico mixed in 1%.

4- If the proof turns into a violet colour it would be because the biuret has react with the sulfato cuprico, showing that there are proteins.

Practice 5: Determination of lipids

DETERMINATION OF LIPIDS

We'll do some experiments:



- Insolubility in water

1.- We take some olives and we cut the pulp into very little pieces.

2.- We throw the pulps in a test tube and we add more or less 5 cm. of water (even level the test tube).

3.- We wave the tube to mix them and we let them rest.

4.- After resting, we can see how some drops of a yellow color have just formed due to the slags are insolubly in water and for his minor density they place on the water.



- Solubility in dissolvents

1.- We catch the pulp of an olive and we make some incisions of her.

2.- A time cutted, we through her in a test tube and we add 2 cm3 of eater.

3.- We let rest the mixture (eater with dissolver slags) and we through in a sump of porcelain or glass.

4.- We evaporate the liquid in fire and we'll obtain some drops of oil.

Practise 6: Oil extraction

This exercise is comparated with the process of an "olive oil mill" in the oil extraction, but in the laboratory.
1- Grind trituration:
We get 100 olives and we take off the bones. We mold the pulp of all the olives with a mixter (in the alamzara industrial the olives are grind with mills or metallic grinds).
2- Milkshake:
When we have the olives grind, it adds a bit of cold water. We remove slowly the paste with a little spoon, while we put it in slow fire for it can warm up, in this way the oil extraction will be more easy.
3- Pressed:
We put the strainer on a hasty cup, we add bit by bit the paste on the strainer to separate the liquid from the solid part. In the almazara industrial it separates the liquid from the solid part with a press system or by spining.
4- Pour off:
When the orujo liquid is separated inthe glass of hastys, we let it separate by pour off during a week in 3 different phases: the first is oil, the second is the alpechín and the third is the remaining orujo, all of them differenciated.
5- Oil separation:
With a pippet, we extract the oil carefuly and we pour it in a test tube.
6- Centrifugation:
Finally, we could centrifuge this oil to finish of separate it from other wastes and it seems clean.

Practise 7: reaction of saponification

The saponification is a chemistry reaction between a lipid and a base. The acids fats of the lipids are dificult to hidrate but can brake easily if the lipid is in a basic enviroment.
1-the original recipe to make soap recomendid to use 6 litres of oil or fat, 5 1/2 litres of water and 1 kg of hidroxid sodiam.
2-However, because we have obtained little oil, we are going to redo the calculations to make soap with only 2 ml of oil.
For it, start by calculating the quantity of water that we need in relation to the oil.
Now calculate the quantity of NAOH in relation with the water.
3-Realise in a test tube the disolution of sodium and water with calculated quantity. We more it till the completed disolution of the sodium.
4- Then we add 2ml of oil and we continue moving little by little till it makes the soap.
5-We remove the soap from the tube and we lay it on a petri plaque, and we leave it in the shape of a bar and we leave it to set.
6-After removing the soap we add water to the tube which we done the experiment in and shake it. The abundance foam of the soap indicates us that there is still soap in it.

Practise 8- Oil preparation to eat

Olives are bitter after its harvesting, thats why they must be prepared to adapt them and to make them pleasant for its consumption. Listen well to the instructions that they are going to give you and write all of the steps.