Freezing food preserves it from the time it is prepared to the time it is eaten. Since early times, farmers, fishermen, and trappers have preserved grains and produce in unheated buildings during the winter season. Freezing food slows down decomposition by turning residual moisture into ice, inhibiting the growth of most bacterial species. In the food commodity industry, there are two processes: mechanical and cryogenic (or flash freezing). The freezing kinetics is important to preserve the food quality and texture. Quicker freezing generates smaller ice crystals and maintains cellular structure. Cryogenic freezing is the quickest freezing technology available due to the ultra low liquid nitrogen temperature −196 °C (−320 °F).
The earliest use of the term in the post-industrial age appears to be in 1946 in The Farmer, a quarterly magazine published and edited from his farm by F. Newman Turner, a writer and pioneering organic farmer. The magazine sponsored the establishment of the Producer Consumer Whole Food Society Ltd, with Newman Turner as president and Derek Randal as vice-president. Whole food was defined as "mature produce of field, orchard, or garden without subtraction, addition, or alteration grown from seed without chemical dressing, in fertile soil manured solely with animal and vegetable wastes, and composts therefrom, and ground, raw rock and without chemical manures, sprays, or insecticides," having intent to connect suppliers and the growing public demand for such food. Such diets are rich in whole and unrefined foods, like whole grains, dark green and yellow/orange-fleshed vegetables and fruits, legumes, nuts and seeds.
Food poisoning has been recognized as a disease since as early as Hippocrates. The sale of rancid, contaminated, or adulterated food was commonplace until the introduction of hygiene, refrigeration, and vermin controls in the 19th century. Discovery of techniques for killing bacteria using heat, and other microbiological studies by scientists such as Louis Pasteur, contributed to the modern sanitation standards that are ubiquitous in developed nations today. This was further underpinned by the work of Justus von Liebig, which led to the development of modern food storage and food preservation methods. In more recent years, a greater understanding of the causes of food-borne illnesses has led to the development of more systematic approaches such as the Hazard Analysis and Critical Control Points (HACCP), which can identify and eliminate many risks.
Edible animal material, including muscle, offal, milk, eggs and egg whites, contains substantial amounts of protein. Almost all vegetable matter (in particular legumes and seeds) also includes proteins, although generally in smaller amounts. Mushrooms have high protein content. Any of these may be sources of essential amino acids. When proteins are heated they become denatured (unfolded) and change texture. In many cases, this causes the structure of the material to become softer or more friable – meat becomes cooked and is more friable and less flexible. In some cases, proteins can form more rigid structures, such as the coagulation of albumen in egg whites. The formation of a relatively rigid but flexible matrix from egg white provides an important component in baking cakes, and also underpins many desserts based on meringue.
In 2013 Overseas Development Institute researchers showed that rice has more than doubled in price since 2000, rising by 120% in real terms. This was as a result of shifts in trade policy and restocking by major producers. More fundamental drivers of increased prices are the higher costs of fertiliser, diesel and labour. Parts of Asia see rural wages rise with potential large benefits for the 1.3 billion (2008 estimate) of Asia's poor in reducing the poverty they face. However, this negatively impacts more vulnerable groups who don't share in the economic boom, especially in Asian and African coastal cities. The researchers said the threat means social-protection policies are needed to guard against price shocks. The research proposed that in the longer run, the rises present opportunities to export for Western African farmers with high potential for rice production to replace imports with domestic production.
Literary references to wine are abundant in Homer (8th century BC, but possibly relating earlier compositions), Alkman (7th century BC), and others. In ancient Egypt, six of 36 wine amphoras were found in the tomb of King Tutankhamun bearing the name "Kha'y", a royal chief vintner. Five of these amphoras were designated as originating from the king's personal estate, with the sixth from the estate of the royal house of Aten. Traces of wine have also been found in central Asian Xinjiang in modern-day China, dating from the second and first millennia BC.
The ideal temperature for serving a particular wine is a matter of debate by wine enthusiasts and sommeliers, but some broad guidelines have emerged that will generally enhance the experience of tasting certain common wines. A white wine should foster a sense of coolness, achieved by serving at "cellar temperature" (13 °C (55 °F)). Light red wines drunk young should also be brought to the table at this temperature, where they will quickly rise a few degrees. Red wines are generally perceived best when served chambré ("at room temperature"). However, this does not mean the temperature of the dining room—often around 21 °C (70 °F)—but rather the coolest room in the house and, therefore, always slightly cooler than the dining room itself. Pinot noir should be brought to the table for serving at 16 °C (61 °F) and will reach its full bouquet at 18 °C (64 °F). Cabernet Sauvignon, zinfandel, and Rhone varieties should be served at 18 °C (64 °F) and allowed to warm on the table to 21 °C (70 °F) for best aroma.
In 1994, over 100 countries became signatories to the Uruguay Round of the General Agreement on Tariffs and Trade in a dramatic increase in trade liberalization. This included an agreement to reduce subsidies paid to farmers, underpinned by the WTO enforcement of agricultural subsidy, tariffs, import quotas, and settlement of trade disputes that cannot be bilaterally resolved. Where trade barriers are raised on the disputed grounds of public health and safety, the WTO refer the dispute to the Codex Alimentarius Commission, which was founded in 1962 by the United Nations Food and Agriculture Organization and the World Health Organization. Trade liberalization has greatly affected world food trade.
Wine tasting is the sensory examination and evaluation of wine. Wines contain many chemical compounds similar or identical to those in fruits, vegetables, and spices. The sweetness of wine is determined by the amount of residual sugar in the wine after fermentation, relative to the acidity present in the wine. Dry wine, for example, has only a small amount of residual sugar. Some wine labels suggest opening the bottle and letting the wine "breathe" for a couple of hours before serving, while others recommend drinking it immediately. Decanting (the act of pouring a wine into a special container just for breathing) is a controversial subject among wine enthusiasts. In addition to aeration, decanting with a filter allows the removal of bitter sediments that may have formed in the wine. Sediment is more common in older bottles, but aeration may benefit younger wines.
Some people have allergies or sensitivities to foods which are not problematic to most people. This occurs when a person's immune system mistakes a certain food protein for a harmful foreign agent and attacks it. About 2% of adults and 8% of children have a food allergy. The amount of the food substance required to provoke a reaction in a particularly susceptible individual can be quite small. In some instances, traces of food in the air, too minute to be perceived through smell, have been known to provoke lethal reactions in extremely sensitive individuals. Common food allergens are gluten, corn, shellfish (mollusks), peanuts, and soy. Allergens frequently produce symptoms such as diarrhea, rashes, bloating, vomiting, and regurgitation. The digestive complaints usually develop within half an hour of ingesting the allergen.
Camping food includes ingredients used to prepare food suitable for backcountry camping and backpacking. The foods differ substantially from the ingredients found in a typical home kitchen. The primary differences relate to campers' and backpackers' special needs for foods that have appropriate cooking time, perishability, weight, and nutritional content.