Etiket Arşivleri: starch

Characteristics of Starch

Characteristics of Starch

Storage form of carbohydrates in plants

Sources:

Cereal endosperm

Wheat

Corn

Roots and tubers

Cassava

Potatoes

Hot water + Starch = Lump formation

Starch granules must first be separated

4 ways:

Coat starch granules with hot fat

Coat starch granules with cold fat

Disperse starch in cold water

Separate granules using sugar

Gelatinization

Starch heated with water

Viscosity increases

Maximum viscosity occurs @ 194°C

Pasting

Occurs when heated beyond gelatinization

Becomes pasty and swollen

Composition of Starch

Amylose

Linear chain of glucose molecules

Source: Cereal starches

Include wheat and corn

Thicken near boiling point

Retrogradation occurs when chilled

Becomes rubbery

Loses water

Composition of Starch

Amylopectin

Branched chain of glucose molecules

Source: Roots and tubers

Include potato and tapioca

Thicken at lower temp.

Becomes clear

No retrogradation occurs

Starch principles

Browning

Dextrinization produces pyrodextrins

Reduced thickening ability occurs

Factors affecting properties of starch

Temperature

Length of treatment

Agitation


Pregelatinezed Starch ( Gamze ÇELİK )

  • FE-401 FOOD TECHNOLOGY

Gamze ÇELİK

Rafia ÇETİNTAŞ

Rojda DAKAK

Zehra DEMİRCİ

Simge Deveci

Huriye Hazal ERDOĞAN

SUPERVISIOR : PROF.DR.ŞENOL İBANOĞLU

  • STARCH

  • Polysaccharide carbohydrate

  • Consisting of a large number of glucose units

  • Joined together by glycosidic bonds.

  • Consist of amylose and amylopectin

  • Produced by all green plants as an energy store

  • Corn Starch

  • Nutrition value of corn starch

  • Carbohydrate:88.8%

       –Diatary fiber:0.5%

       –Carbohydrate, available:88.3%

  • Fat:0.6%

  • Protein:0.4%

  • Moisture Content:10.2%

  • Energy:1534 kj

MODIFIED STARCH ?

Modified starch is a food additive which is prepared by treating starch causing the starch to be partially degraded.

  • Purpose of modification

  • The purposes of this modification are to enhance its properties particularly in specific applications such as to improve the increase in water holding capacity, heat resistant behavior, reinforce its binding, minimized syneresis of starch and improved thickening

METHODS OF MODIFICATION

  • Hydrolysis

  • Oxidation

  • Cross-linking

  • Pregelatinization

Modified starch has many uses in food products:

  • PREGELATINIZATION

  • Starch gelatinization is a process of breaking down the intermolecular bonds of starch molecules in the presence of water and heat.

  • PROPERTIES OF PREGELATINIZED STARCH

High water binding capacity

High digestibility

High viscosity

Water soluble

Chemically more active

Low crystallinity

WHY DRUM DRYER?

  • Suitable for very viscous food material

  • Quick method

  • Large heating surface

  • Requires small space for operation.

  • Efficient

  • PROCESS LINE DIAGRAM

  • Stirring

  • Stirring process is applied to get dough from starch with addition of 35-40 % water.

  • Starch slurry occur in %40 water and %60 starch.

  • A concentrated aqueous starch slurry, consisting of unmodified raw starch.

  • Process is fed to the roll with dip feed type feeding.

  • Temperature of stirring is 320C

  • Drum dryer

  • It is consist of a drum of about 0.75-1.5 m in diameter and 2-4 m length, heated internally usually by steam and rotated on its horizontal axis.

  • Inlet steam temperature range 180 0C-200 0C.

  • Drum Surface Temperature :120-1700C

  • Drum Rotation Speed :2-6 rpm

  • Collection

Dry products from drum dryer are collected.

These products are sent to the hammer milling.

  • Hammer Milling

    A hammer mill is a mill whose purpose is to shred or crush aggregate material into smaller pieces by the repeated blows of little hammers.

  • PACKAGING

  • EQUIPMENT LIST

  • Steam generator,

  • Rotary drum heater,

  • Steam pressure meter,

  • Water drainage valve,

  • Material distribution pipeline,

  • Flow regulating valves,

  • Discharge scraper,

  • Material collecting hopper.

  • CRITICAL PARAMETERS

  • Water Content

  • Drum Surface Temperature :120-1700C

  • Drum Rotation Speed :2-6 rpm

  • CONTROL POINTS

  • Dust formation

  • Metal detection

  • PROPERTIES OF FINISHED PRODUCT

Physical Properties

  • Appearance : Fine white powder

  • Smell : Neutral

  • Shape: Not uniform, like ellipsoidal

  • Color : White

  • Swelling capacity : increased

  • High water solubility

  • High water absorption

  • Viscosity : increased

  • Size of the starch granules : reduced

  • Moisture content : 8 % max.


What is starch?

SOURCES OF STARCH

Starch or amylum is a carbohydrate consisting of a large number of glucose units joined together by glycosidic bonds; It is the most important carbohydrate in human diet; It is produced by all vegetables as an energy store: it is contained in cereals such as wheat, corn and rice or in tubers such as potatoes and cassava.

STARCH PRODUCTS

Pure starch is a white, tasteless and odourless powder that is insoluble in cold water or alcohol. It can be used as such in processed foods or in the paper industry; Glucose syrups are liquids which are used in the food industry for their sweetening power and for other numerous functionalities or as a fermentescible substrate.Starch and glucose can be transformed into modified starches or different kinds of sweetening products which are used in the food industry.

….

STARCH USES IN FOOD

Anti-crystallising in confectioneries;

Sweetening power in beverages;

Bulking agent / texture in dairy products;

Preservatives in jams;

Moistening in bakery products;

Freezing point depression in ice creams

Thickening, binding agent in soups & sauces;

Browning effect in caramels;

Cooling effect in chewing-gum;

Low glycemic index in dietetic food…

Enzymatic Process for High Glucose Production using Granular Starch

Current Process for Glucose Production

Brief History of Granular Starch Hydrolysis

Granular Starch Hydrolyzing Enzymes (GSHE) For Glucose

Production

Proposed Process

Summary and What is next ?

Starch & Glucose Syrup

STARCH & GLUCOSE SYRUP

Starch a linear fraction amylose & a branched fraction amylopectin.
Most starches contain about 20-39 % amylose
Normal starch contain 70-80% amylopectin while waxy starch contains almost 100 % amylopection
Physical Quality of Starch
Size Distribution
Determines its swelling functionality with granules
Solubility
Starch is not soluble in water
Viscosity
High gelatinized temperatures, high viscosity
Taste
Critical for dairy products, e.g. yogurt
Color
Chemical Quality of Starch
Gelatinization
With higher temperatures granules begins to swell and loses maltese crosses (60-70 oC)
Birefringence
The loss of birefringence determine gelatinization temperature
Starch paste
Viscous mixture of gelatinized starch and liquid
Retrogradation
Crystallization of starch chains in gel
Microbiological Quality of Starch
α-amylases
active at the high temperatures of gelatinization (100-110°C) and liquefaction (80-90°C) to economize processes
therefore there has been a need for more thermophilic and thermostable α-amylases.
Thermostable enzymes from thermophilic organisms
Bacillus, Actinomycetes, Thermomonospora
Physical and Chemical Requirements of Glucose Syrup
Dextrose equivalent
Degree of hydrolysis of the starch, the range of 20 to 75 DE.
Degree of polymerisation
Describes the carbohydrate composition of a syrup
Baumè
Describes the density of specific gravity of a syrup
Physical and Chemical Requirements of Glucose Syrup
Color formation
Maillard reactions
Brown colors in the syrups tend to develop during evaporation or during storage (450C-550C)
Caramelization
Bodying agent
Provide sweetness and mouthfeel
Foam development and stabilization
Low DE products better for emulsion stabilization than high DE products
Physical and Chemical Requirements of Glucose Syrup
Glaze Formation
Low DE glucose for glazing
Used on baked foods to improve their appearance and give some surface protection.
Humectancy
Osmotic pressure and water activity
Glucose syrups
self-preserving, prevent microbial growth
high dissolved solids content in the syrups, binding all the free water
high osmotic pressure and low water activity
Physical and Chemical Requirements of Glucose Syrup
Refractive index
RI increases as the solid content of the syrup increases
RI decreases as the DE of the syrup increases at the same solid content
RI decreases as the temperature of the syrup increases at the same solid content
Specific rotation
Affect the optical and specific rotation of a syrup
Corn
Starch Production
Maize Receipt Quality analysis
Storage
Cleaning Broken maize/debris to animal feed
Steeping Corn steep liquor-fermentation
Coarse milling
Degermination Germ oil extraction
Second milling
Degermination
Fine milling
Fibre seperation Animal feed
Desanding
Gluten seperation Animal feed/fermentation
Starch Refining
Maize Starch Glucose syrups
Corn Starch Production
Maize receipt
üBy a wet milling process, because of maize high oil content
Maize delivery, storage and cleaning
Maize sieves to remove any larger contaminants
Grain is pneumatically transferred to a series of vibratory sieves and winnowing tower to remove both light and heavy contaminations. Broken and damaged nibs removed at this stage
Clean maize nibs are then pneumatically transferred to holding silos
Corn Starch Production
Steeping
Softens the grain to allow milling, moisture content to the optimum for milling
Maize is soaked for 30-50 hours in stainless steel tanks holding at 45-600C using a counter current process
Very important for the quality of starch
Degermination
First stage of the separation process
Release the germ from the endosperm
Germ can be separated from starch, fibre and protein components by its low specific gravity
Corn Starch Production
Fine milling
Produces a finely ground mixture of starch, gluten and fibre
Maximum size reduction of the protein and starch
Fibre fraction is sieved out using multistage bow sieves
Gluten separation
To separate starch from gluten continuous high speed centrifuge is used.
Starch refining
Starch is washed to remove any remaining fibre, gluten and solubles.
End product (starch stream) has 40% dry solids and protein contents less than 0.15%.
Glucose
Syrup Production
Starch Slurry
TEŞEKKÜRLER…

Pregelatinized Starch

PREGELATINIZED STARCH

INSTRUCTOR:
Prof. Dr. Şenol İBANOĞLU
Ayşe YILMAZ
Figen YILMAZ
Sevim YILMAZ
Oğuz YÜKSEL
DEFINITION OF

PREGELATINIZED STARCH

Pregelatinized starch is a processed carbohydrate, used as a texturizer and/or binder. Pregelatinized starch derives primarily from corn starch, has been cooked and then dried.

RAW MATERIALS

CORN STARCH

Corn starch, is the starch derived from the corn (maize) grain. The starch is obtained from the endosperm of the corn kernel. Corn starch is a popular food ingredient used in thickening sauces or soups, and is used in making corn syrup and other sugars.
Nutrition value of corn (raw material):
carbohydrate: 82%
fat: 10%
protein: 8%
Nutrition value of corn starch:
Total carbohydrate: 30%
Dietary fiber: 4%
Protein: 1%
Iron: 3%
Calories: 381 kj/kg

PROCESS LINE DIAGRAM

Stirring process is applied to get dough from starch with addition of 35-40 % water. Drum dryers are film dryers in which the product only comes into direct contact with the necessary drying temperature for a few seconds therefore ensuring particularly quick drying.
With this type of drying, the product to be dried comes into extensive contact with the heated drums.
The short exposure to high temperature reduces the risk of damage to the product. The water or solvent evaporates and leaves the process at the top.
If the necessary, the vapor can also be suctioned off locally around the drum. The dried product layer finally reaches the knife and is scrapped of. After roller dry the products transport to the milling. Product’s transportation occurs in the conveyor.
An extrusion machine is a device which pushes or pulls a material through a shaped die to form a continuous length of product with a preset cross section.
Extrusion as a manufacturing process offers many benefits such as the wide range of complex cross sections possible and the ability to form brittle materials. Depending on the material used, an extrusion machine may form the material cold or hot with some types of materials being completely melted prior to extrusion.

TECHNOLOGIES

Highly Functionalized Corn Starch (HS):

HS has different properties from conventional pregelatinized starches and conventional hydrophilic gel-matrix excipients because of its high viscosity and insoluble element in dissolution media.

EQUIPMENT LIST

Steam generator,
Rotary drum heater,
Valve,
Steam pressure meter,
Water drainage valve,
Extruding rollers,
Material distribution pipeline,
Flow regulating valves,
Discharge scraper,
Material collecting hopper.

IMPORTANT ANALYSIS (C.P.)

Expansion Index (EI)
Bulk Density (BD)
Water absorption index (WAI)
Water solubility index (WSI)
Hunter Color
RVA(Rapid Visco Analyser) Method
Water absorption capacity, solubility and swelling power determination.

CRITICAL PARAMETERS

Sensory Analysis:
•taste
•odor
•texture
Chemical Analysis:
•water activity
•microbial activity
•storage life

PROPERTIES OF FINISHED PRODUCT

Physical Properties
Appearance : Fine white powder
Smell : Neutral
Shape: Not uniform, like ellipsoidal
Color : White

PROPERTIES OF FINISHED PRODUCT

Chemical Properties
Moisture : 8 % max.
Ash : 0.5 % max.
Viscosity : 6 %
Acetyle Content : 1.10 % – 2.00 %

USAGE OF PREGELATINIZED STARCH IN FOOD INDUSTRY

Puddings
Pie fillings
Soup mixes
Salad dressings
Candy
THANKS TO
ŞENOL İBANOĞLU

Pregelatinized Starch Report

Starches are typically derived from corn or potato. Starches are used in the pharmaceutical industry for a wide variety of reasons, such as an excipient, a tablet and capsule diluent, a tablet and capsule disintegrant, a glidant, or as binder. Disintegrants enable tablets and capsules to break down into smaller fragments (dissolve) so that the drug can be released for absorption. Starches also absorb water rapidly, allowing tablets to disintegrate appropriately.

Starches are also used in the food manufacturing industry for processing, and as food thickeners or stabilizers. There are many other diverse uses for starches in the manufacturing industry. Pregelatinized starch derives primarily from corn, has been cooked and then dried. Instant puddings, pie fillings, soup mixes, salad dressings, candy often contain pregelatinized starch.

Pregelatinized Starch is a kind of physical modified starch, mainly used as pharmaceutical excipient. In pharma excipients applications, it can be used for direct compression, formulations as binder, disintegrant, flow aid and self lubricant.