SILAHKAN DICARI (15 menit, ditulis dikertas sobekan,
dikumpulkan)
1. Apa pengertian Intermediate Moisture Food?
2. Sebutkan contoh produk-produk IMF dari buah!
3. Apakah perbedaan jam and jellies?
4. Sebutkan bahan utama penyusun jam and jellies!
Intermediate Moisture Food (IMF)
adalah bahan pangan yang mempunyai kandungan air 10 - 50% dan aw sekitar 0,6 – 0,9. Produk ini stabil
pada suhu kamar, bersifat plastis & tidak kering.
Characteristic:
Moisture content : 10-50%
Water activity (a
w) : 0.6-0.9
Texture : soft, plastic
a w of some traditional IMF
Dried fruits 0.60-0.75
Cake and pastry 0.60-0.90
Frozen foods 0.60-0.90
Ready-to-eat-cereals 0.65-0.75
Jams 0.80-0.910
Fermented sausages 0.83-0.87
Sweetened condensed milk 0.83
Jams
made by cooking crushed/chopped fruit with sugar
Jellies
made by cooking fruit juice with sugar
Preserves
spread with small whole fruit/fruit pieces in a slightly gelled syrup
Conserves
jam-like, may contain a mix of fruits, nuts,
raisins, or coconut
Marmalades
soft fruit jellies with small pieces of
fruit/peel – often citrus
Fruit butters
fruit pulp cooked with sugar until thick, not gelled
Jams and Jellies
Fruits
Sugar
Acid
Pectin
Jam and Jelly
Fruit : gives each product its characteristic color and flavor.
Use at least some flavorful, just-ripe fruit in each recipe.
Canned, frozen or dried fruit also able to be used.
Use canned or frozen fruits preserved without sugar.
Thaw frozen fruit in the refrigerator before using.
Cook dried fruit in water until tender and use to make jams and conserves.
Pectin : the natural plant substance (carbohydrate) that causes fruit to gel, and there are many options available now for pectin
Acid : essential in jellied fruit products for both gel formation and flavor.
The acid content varies among fruits, and is higher in under- ripe fruits.
Sugar : helps the gel formation, and contributes to flavor.
Use the amount of sugar a recipe calls for.
To make a low-sugar or no-sugar product, choose a pectin or research-tested recipe designed for this.
Sugar substitutes — also called artificial sweeteners —
cannot replace sugar in regular recipes because the sugar is needed to form a gel.
Pectin
Use natural pectin in apples and grapes
Fruits such as apples, currants, and grapes contain enough natural pectin to form a gel.
Add pectin to other fruits or fully ripe fruits to ensure a good gel
Adding pectin to any fruit can ensure a good gel, and there are several advantages for doing this:
We can use fully ripe, flavorful fruit
Cooking time is shorter so we retain more of the natural color and flavor of the fruit
We will have more jars on the shelf from the same amount of fruit.
How to know the pectin contain in fruit?
→ alcohol test
Dry & powdered pectin for different recipes
Regular pectin work with sugar, fruit and acid to form a gel.
Regular pectin comes in two types : liquid (such as Certo) and powdered (such as Sure-Jell).
Liquid pectin is added to a hot pre-cooked mixture of sugar and fruit and cooked for 1 more minute
Powdered pectin is cooked with fruit, then sugar is added and the mixture is cooked for 1 more minute.
The two types of pectin are not interchangeable.
Low-methoxyl pectins for low- or no sugar products
Low-methoxyl pectins are chemically different from regular pectins and can gel with little or no added sugar.
The resulting gel will be softer, but this can be
acceptable for those on a low-sugar or no-sugar diet.
The product also tends to be less sweet, and to have a fruiter taste.
Even commercial manufacturers are taking advantage of this type of gelling agent to produce high quality products.
Powdered gelatin for refrigerator products
No sugar refrigerator products may call for powdered gelatin as the gelling agent.
Powdered gelatin is a protein, unlike pectin which is a carbohydrate.
Gelatin must be treated carefully or the gel structure will break. So, do not freeze these jellies and do not can these products. Store them in the refrigerator.
Pengolahan buah
-Jam / Selai - Jelly - Marmalade
- Preserve Pektin
Rantai ikatan
1 – 4 D-asam galakturonat Berupa ester dengan
metil-alkohol
Protopektin
(Sbg bhn dasar pektin)
Protopektinase Hidrolisis
Water Soluble
Water Insoluble Buah
Under Ripe
Buah Under Mature
Daya Jelly (Gelatinisasi)
Kadar Metoksil (-COO-CH3) Ditentukan
Acids
Acid is essential in jellied fruit products.
Sometimes the acid comes from under-ripe fruit, and sometime it is added in the form of bottled lemon juice.
Sugar
Added sugar preserves jellied fruit by inhibiting the growth of microbes, helps form the gel, and adds flavor.
Measure sugar carefully and do not reduce the amount in the recipe.
Beet and cane sugar will work equally well. Using brown sugar is not recommended because of the dark color it imparts to the finished product.
Honey or light corn syrup can be used, but
remember that liquid ingredients must be adjusted
accordingly.
Sugar substitutes can NOT substitute for sugar if using regular pectin.
It only can be used when making jams and jellies with low-methoxyl pectin.
Sugar substitutes such as sucralose (Splenda) and
saccharin (Sweet-n-Low) tend to hold up well during heating. Follow the manufacturer’s directions for using these products. Do not use aspartame (Equal or
Nutrasweet) as the resulting product will be
unsatisfactory.
Buah
Sortasi
Pencucian
Trimming
Pembuburan
Pencampuran
Pemasakan
Pengemasan
Pendinginan
Jam/selai dlm kemasan
Buah afkir
Air bersih Air sisa
Bag. Yg tdk digunakan
Gula, pektin, dan asam
Pasteurisasi
Diagram Alir Pengolahan Jam / Selai
Buah
Sortasi
Pencucian
Trimming
Penggodogan
Pemerasan
Filtrasi
Pencampuran
Penggodogan
Pengemasan
Pendinginan
Jelly dlm kemasan
Buah afkir
Air bersih Air sisa
Bag. Yg tdk digunakan
ampas
Sari buah
Partikel sisa
Gula, asam, dan pektin
Diagram Alir Pengolahan Jelly
How to know sufficient cooking of jam and jelly?
Spoon test
Soluble solid reaches 65%
(68%) . This is most
conveniently measured using a hand-held refractometer.