Tuesday, 27 June 2017
‘Pressure cook’ food waste to make fuel faster
A two-step method that includes hydrothermal liquefaction and anaerobic digestion can speed up the process of making biofuel from food waste while reducing carbon use, new research suggests.
"Food waste should have a high value. We're treating it as a resource, and we're making marketable products out of it," says lead author Roy Posmanik, a postdoctoral researcher at Cornell University. "Food waste is still carbon—a lot of carbon."
The researchers show that by using hydrothermal liquefaction before anaerobic digestion, virtually all of the energy is extracted from the food waste. In hydrothermal liquefaction, the waste is basically pressure cooked to produce a crude bio-oil. That oil can be refined into biofuel.
The remaining food waste, which is in an aqueous state, is anaerobically digested by microbes within days. The microbes convert the waste into methane, which can be used to produce commercial amounts of electricity and heat.
"If you used just anaerobic digestion, you would wait weeks to turn the food waste into energy," says Posmanik.
"The aqueous product from hydrothermal processing is much better for bugs in anaerobic digestion than using the raw biomass directly. Combining hydrothermal processing and anaerobic digestion is more efficient and faster. We're talking about minutes in hydrothermal liquefaction and a few days in an anaerobic digester," Posmanik says.
Food waste is the single largest component going into municipal landfills in the United States, according to the US Department of Agriculture. About one-third of the world's food—nearly 1.3 billion tons—is lost or wasted, according to the Food and Agriculture Organization of the United Nations.
For all industrialized nations, food waste accounts for roughly $680 billion annually. In addition, composting and digestion of food waste are inefficient and slow.
Putting hydrothermal liquefaction first in an engineering process and finishing with anaerobic digestion completes a food-water-energy nexus, Posmanik says.
"We must reduce the amount of stuff we landfill, and we must reduce our carbon footprint. If we don't have to extract oil out of the ground to run cars or if we're using anaerobic digestion to make green electricity, we're enhancing energy and food security," he says.
Friday, 26 May 2017
Memorial Day 2017 Cookout Ideas: The Healthiest Ways To Cook These 6 Foods, Based On Science
Memorial Day weekend kicks off the start to the breezy summer lifestyle, which means it's time for open beaches, outdoor drinking, and grilling. Everybody loves a backyard barbeque with lots of food offerings, but unfortunately, many are notoriously high in fat and calories. However, we can still enjoy our summer cookouts without sacrificing our waistline, or our tastebuds.
Grilling can be a healthier alternative to pan frying, deep frying, and even sauteing, depending on how the food is prepared before and how it's being cooked. According to the Academy of Nutrition and Dietetics, dialing down the heat; cutting the fat; marinating meat for at least 30 minutes before grilling; mixing it up with fruits and vegetables; and keeping the grill clean all make a cookout tasty and good for us. To keep grilling healthy, it's best to avoid high-fat meats and sausages.
So, what's the healthiest way to cook Memorial Day BBQ staples?
Medical Daily wrangled the best ways to cook these six foods, from burgers to fish, to satisfy the tastebuds of all.
Burgers
Burgers are a popular BBQ food staple that can be good for us if cooked properly. A study conducted at UCLA found topping a burger with avocado — rich in heart-healthy omega-3 fats — can ease some of the negative effects red meat has on our heart health. The researchers observed 11 healthy males between 18 and 35 eat hamburger patties plain, and then again with half an avocado spread on top. When the participants ate the burger with avocado, their levels of inflammation were lower hours afterward compared to when they ate meat alone. Moreover, avocado led to less reduction of blood flow in the arteries compared to after they ate the plain burger.
Hot Dogs
A Memorial Day Weekend BBQ wouldn't be complete without hot dogs. However, as a processed meat, it's difficult to think of them as healthy. Choosing a healthier hot dog is not easy, but it is possible. It's best to choose hot dogs labeled "nitrate/nitrite free" or "uncured."
These hot dogs contain natural sources of nitrate, often celery juice, extract, or powder, according to Berkeley Wellness. It's not clear whether this will cut the health risks, since they're too new on the market to be studied. But, opting for hot dogs that are made with turkey or chicken instead of beef or pork, or made with organic meat can be good options. It's best to check the label to view its sodium, saturated fat, and nitrate/nitrites.
Chicken
A skinless cut of chicken is known to have less fat and calories, while a skin-on cut can have similar nutritional value if the skin is removed before eating, according to a study conducted by Chicken Farmers of Canada. For example, skinless chicken breast has 146 calories and 1.73 grams of fat compared to chicken breasts cooked with skin and skin removed, with 134 calories and 1.37 grams of fat per 100 grams; this means chicken breast cooked with skin-on, and then removed, has less fat and calories than a skinless breast. Plus, skinless chicken breast has less moisture than chicken with skin and skin removed at 64.96 grams vs. 67.47 grams, respectively.
Fish
Cookouts are not just for meat lovers, they can also appease non-meat eaters. Fish is considered one of the healthiest foods; it's rich in omega-3, vitamin D, and essential oils, but how we cook it matters. A study conducted at the University of Pittsburgh School of Medicine found participants who regularly ate fish had larger brain volumes in regions associated with memory and cognition, but only if the fish was baked or broiled, and not fried. Cooking fish on the grill can also help lock in flavor, without removing much moisture.
Mushrooms
This fungi is an excellent source of fiber and vitamins, but this is all dependent on how they're cooked. A recent study found microwaving and grilling mushrooms are the best ways to help preserve their antioxidant properties, and even increase their antioxidant activity. Moreover, mushrooms are also very low in calories and fat, making them a diet-friendly food.
Vegetables
In cookouts, balance is key, which means there should be equilibrium between the amount of meat, fish, and fruits and vegetables we consume. Vegetables have been tied to a lower risk of high blood pressure, macular degeneration, cognitive decline, and digestive tract cancers, among other ailments. However, cooking methods can alter their nutrient composition, and destroy their nutritional benefits, while others enhance their nutrient content.
Dry cooking methods like grilling, roasting, and stir-frying retain greater amounts of nutrients than boiling. This also debunks the myth that eating raw vegetables is healthier than cooking. For example, a 2002 study found that cooking tomatoes actually boosts the amount of lycopene in tomatoes.
Remember, grilling your favorite cookout foods can be done, without the guilt.
Grilling can be a healthier alternative to pan frying, deep frying, and even sauteing, depending on how the food is prepared before and how it's being cooked. According to the Academy of Nutrition and Dietetics, dialing down the heat; cutting the fat; marinating meat for at least 30 minutes before grilling; mixing it up with fruits and vegetables; and keeping the grill clean all make a cookout tasty and good for us. To keep grilling healthy, it's best to avoid high-fat meats and sausages.
So, what's the healthiest way to cook Memorial Day BBQ staples?
Medical Daily wrangled the best ways to cook these six foods, from burgers to fish, to satisfy the tastebuds of all.
Burgers
Burgers are a popular BBQ food staple that can be good for us if cooked properly. A study conducted at UCLA found topping a burger with avocado — rich in heart-healthy omega-3 fats — can ease some of the negative effects red meat has on our heart health. The researchers observed 11 healthy males between 18 and 35 eat hamburger patties plain, and then again with half an avocado spread on top. When the participants ate the burger with avocado, their levels of inflammation were lower hours afterward compared to when they ate meat alone. Moreover, avocado led to less reduction of blood flow in the arteries compared to after they ate the plain burger.
Hot Dogs
A Memorial Day Weekend BBQ wouldn't be complete without hot dogs. However, as a processed meat, it's difficult to think of them as healthy. Choosing a healthier hot dog is not easy, but it is possible. It's best to choose hot dogs labeled "nitrate/nitrite free" or "uncured."
These hot dogs contain natural sources of nitrate, often celery juice, extract, or powder, according to Berkeley Wellness. It's not clear whether this will cut the health risks, since they're too new on the market to be studied. But, opting for hot dogs that are made with turkey or chicken instead of beef or pork, or made with organic meat can be good options. It's best to check the label to view its sodium, saturated fat, and nitrate/nitrites.
Chicken
A skinless cut of chicken is known to have less fat and calories, while a skin-on cut can have similar nutritional value if the skin is removed before eating, according to a study conducted by Chicken Farmers of Canada. For example, skinless chicken breast has 146 calories and 1.73 grams of fat compared to chicken breasts cooked with skin and skin removed, with 134 calories and 1.37 grams of fat per 100 grams; this means chicken breast cooked with skin-on, and then removed, has less fat and calories than a skinless breast. Plus, skinless chicken breast has less moisture than chicken with skin and skin removed at 64.96 grams vs. 67.47 grams, respectively.
Fish
Cookouts are not just for meat lovers, they can also appease non-meat eaters. Fish is considered one of the healthiest foods; it's rich in omega-3, vitamin D, and essential oils, but how we cook it matters. A study conducted at the University of Pittsburgh School of Medicine found participants who regularly ate fish had larger brain volumes in regions associated with memory and cognition, but only if the fish was baked or broiled, and not fried. Cooking fish on the grill can also help lock in flavor, without removing much moisture.
Mushrooms
This fungi is an excellent source of fiber and vitamins, but this is all dependent on how they're cooked. A recent study found microwaving and grilling mushrooms are the best ways to help preserve their antioxidant properties, and even increase their antioxidant activity. Moreover, mushrooms are also very low in calories and fat, making them a diet-friendly food.
Vegetables
In cookouts, balance is key, which means there should be equilibrium between the amount of meat, fish, and fruits and vegetables we consume. Vegetables have been tied to a lower risk of high blood pressure, macular degeneration, cognitive decline, and digestive tract cancers, among other ailments. However, cooking methods can alter their nutrient composition, and destroy their nutritional benefits, while others enhance their nutrient content.
Dry cooking methods like grilling, roasting, and stir-frying retain greater amounts of nutrients than boiling. This also debunks the myth that eating raw vegetables is healthier than cooking. For example, a 2002 study found that cooking tomatoes actually boosts the amount of lycopene in tomatoes.
Remember, grilling your favorite cookout foods can be done, without the guilt.
Saturday, 8 April 2017
Recipe for an Italian Easter: egg, spinach and ricotta pie
One Easter, when I was 11 years old, I carefully stained both marzipan and my hands in orange, green and red, shaping my own oranges, apples and pears, with cloves providing a stalk for each. I then gave a box of them to my auntie. Two years later, while looking in her drawers for something, I found the box, unopened, and my face burned with embarrassment.
The marzipan fruits in the window of one of our local patisseries in Gela, in Sicily, also appear to have been there some time. Years I’d guess, judging by the almost waxy hue of the carefully moulded and painted peaches, prickly pears, figs and cherries. It crossed my mind that they might actually be wax – a Sicilian version of the sushi replicas you see in Japanese restaurant windows, but I am assured they are real. These frutta martorana shaped from pasta reale (a type of marzipan) are traditionally made in Sicily for All Souls Day in November, when the dead bring them to the children who have prayed for their souls. Nowadays you find them all year round. Even when ageing, they are exquisite things, a riot of colour and dexterity, and they almost seem real.
Inside the out-of-time shop, behind the glass cabinet doors and between the pictures and statues of the Madonna, there are also marzipan artichokes, prawns and snails. They appear younger. In fact, that first visit in May, I imagine they are from the previous autumn. There are also lambs fashioned from marzipan, covered with a fleece of white icing, their faces painted. Quite beautiful things really – a sweet sacrifice for Easter, the sort my partner Vincenzo was given every year as a child. At the front of the shop, inside the altar-like counter, are half a dozen varieties of plump soft almond biscuits, so we buy a trayful – also a lamb and a coral-coloured prawn.
Italy’s year is punctured with festivities and saint days – each one with its own dish, bun, bread or biscuit. Patisseries and bakery windows remind us almost as effectively – and certainly more deliciously – than a calendar. Easter is the most sacred and celebrated, both in religious ritual and at the table, the food seeming even richer after the austerity of lent, maybe. Each region has an Easter dish, specialty pies and the usual daily breads, but enriched, containing or encasing eggs – the ultimate symbol of hope, renewal and fertility; new life contained in a delicate shell.
Rather like Christmas, the traditions we string together are always slightly different. Some years I’ve felt the need to expatriate the Easters of my childhood, others times I’ve tried too hard to be Italian. The best times are when I settle in the middle, knowing we make our own traditions and that they are always evolving: an enriched bread from Rome, a pie from somewhere else, my son with Creme Egg in one hand and lamb in the other. I am going back to the UK this year, so will take back edible pieces of Italy: salami, cheese and colomba. Like its cousin panettone, colomba is made from dough enriched with eggs, butter and candied fruit – an augury of plenty topped with pearl sugar and almonds then baked into the shape of a colomba, which means dove. Mine possibly won’t look so peaceful after a plane and two trains, but will be enjoyed nonetheless.
It is the festive breads and pies plumped with eggs and cheese I enjoy best, so I always make one for Easter breakfast, or the picnic on Easter Monday. I particularly appreciate the Ligurian torta pasqualina: greens, herbs and ricotta encased in olive oil dough rolled so thin it is rather like filo pastry. Traditionally there were 33 layers, one for each year of Jesus’s life. The version I have adopted is not traditional and rather more pragmatic in its use of Marcella Hazan’s pastry with ricotta (instead of eggs), which makes for a pleasing and flaky crust. For the filling you can use wilted beet greens, chard or spinach, which you mix with ricotta and parmesan and then season boldly. This filling then cradles more eggs.
“Behold”, the Sicilian food writer Pino Correnti writes, about cutting into a dish and his joy at discovering an egg at its heart, the yolk shining as hopefully as the sun. Cutting this pie makes me feel much the same.
Ricotta, spinach and egg easter tart – torta pasqualina
Serves 6-8
160g cold butter, diced
250g plain flour
200g ricotta
Salt and black pepper
600g spinach or chard
300g ricotta
6 eggs plus extra for brushing
80g parmesan, grated
A pinch of nutmeg
1.Make the pastry by rubbing the butter into the flour with your fingertips until it resembles breadcrumbs. Add the ricotta and a pinch of salt, mix and bring together into a soft ball. Turn the pastry on to a floured work surface and knead until smooth. Cover with clingfilm and chill for 30 minutes.
2.Pick the over the spinach, discarding any tough or discoloured leaves, then wash and lift into a pan – there will be residual water from the washing. Put the pan over a low-medium heat and cover for a few minutes to wilt the spinach. Tip into a colander and drain for 10 minutes.
3.Once the spinach is cool enough to handle, squeeze out the water then chop roughly. Mix with ricotta, 2 lightly beaten eggs, salt, pepper, parmesan and a pinch of nutmeg.
4.Butter and flour a 26cm round tin, preheat your oven to 190C/375F/gas mark 5 and put a flat baking tray in to get hot. Cut the dough into two uneven pieces, one twice the size of the other. On a floured work surface roll the larger piece into a circle large enough to fill the tin, come up the sides and overhang. Lift the dough into the tin and press it into the corners. Add your filling, making four deep indents in the mixture, into which break the eggs.
5.Roll the smaller piece into a disc the size of the tin and lift on to the filling. Using wet fingertips, press the dough to make a firm seal and then lift and fold any excess dough into the centre. Prick or slash the centre of the tart. Paint with beaten eggs or milk, put on the hot baking tray, and slide into the oven for 50 minutes or until golden. Allow to cool a little before turning out. Serve warm or at room temperature.
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