Found this useful list of foods containing 50g of carbs here:

Food Portions Providing 50 g of Carbohydrate

CEREAL
Wheat biscuit cereal (e.g. Weet Bix) 60g (5 biscuits)
'Light' breakfast cereal (e.g. Cornflakes) 60 g (2 cups)
'Muesli' flake breakfast cereal 65 g (1-1.5 cups)
Toasted muesli 90 g (1 cup)
Porridge - made with milk 350 g (1.3 cups)
Porridge - made with water 550 g (2.5 cups)
Rolled oats 90 g (1 cup)
Bread 100 g (4 slices white or 3 thick wholegrain)
Bread rolls 110 g (1 large or 2 medium)
Pita and lebanese bread 100 g (2 pita)
Chapati 150 g (2.5)
English muffin 120 g (2 full muffins)
Crumpet 2.5
Muesli bar 2.5
Rice cakes 6 thick or 10 thin
Crispbreads and dry biscuits 6 large or 15 small
Fruit filled biscuits 5
Plain sweet biscuits 8-10
Cream filled/chocolate biscuits 6
Cakestyle muffin 115 g (1 large or 2 medium)
Pancakes 150 g (2 medium)
Scones 125 g (3 medium)
Iced fruit bun 105 g (1.5)
Croissant 149 g (1.5 large or 2 medium)
Rice, boiled 180g (1 cup)
Pasta or noodles, boiled 200 g (1.3 cups)
Canned spaghetti 440 g (large can)
FRUIT
Fruit crumble 1 cup
Fruit packed in heavy syrup 280 g (1.3 cups)
Fruit stewed/canned in light syrup 520 g (2 cups)
Fresh fruit salad 500 g (2.5 cups)
Bananas 2 medium-large
Large fruit (mango, pear, grapefruit etc.) 2-3
Medium fruit (orange, apple etc.) 3-4
Small fruit (nectarine, apricot etc.) 12
Grapes 350 g (2 cups)
Melon 1,000 g (6 cups)
Strawberries 1,800 g (12 cups)
Sultanas and raisins 70 g (4 Tbsp)
Dried apricots 115 g (22 halves)
VEGETABLES
Potatoes 350 g (1 very large or 3 medium)
Sweet potato 350 g (2.5 cups)
Corn 300 g (1.2 cups creamed corn or 2 cobs)
Green Beans 1,800 g (14 cups)
Baked beans 440 g (1 large can)
Lentils 400 g (2 cups)
Soy beans and kidney beans 400 g (2 cups)
Tomato puree 1 litre (4 cups)
Pumpkin and peas 700 g (5 cups)
DAIRY PRODUCTS
Milk 1 litre
Flavoured milk 560 ml
Custard 300 g (1.3 cup or half 600 g carton)
'Diet' yoghurt and natural yoghurt 800 g (4 individual tubs)
Flavoured non-fat yoghurt 350 g (2 individual tubs)
Icecream 250 g (10 Tbsp)
Fromage frais 400 g (2 tubs)
Rice pudding/creamed rice 300 g (1.5 cups)
SUGARS and CONFECTIONERY
Sugar 50 g
Jam 3 Tbsp
Syrups 4 Tbsp
Honey 3 Tbsp
Chocolate 80 g
Mars Bar and other 50-60 g bars 1.5 bars
Jubes and jelly babies 60 g
MIXED DISHES
Pizza 200 g (medium -1/4 thick or 1/3 thin)
Hamburgers 1.3 Big Macs
Lasagne 400 g serve
Fried rice 200 g (1.3 cups)
DRINKS
Fruit juice - unsweetened 600 ml
Fruit juice - sweetened 500 ml
Cordial 800 ml
Soft drinks and flavored mineral water 500 ml
Fruit smoothie 250-300 ml
SPORTS FOODS
Sports drink 700 ml
Carbohydrate loader supplement 250 ml
Liquid meal supplement 250-300 ml
Sports bar 1-1.5 bars
Sports gels 2 sachets
Glucose polymer powder 60 g