ñañ

Some of the most frequently used methods for food protein determination are based on analysis of the total nitrogen content in the samples. Examples of such methods are the Dumas method [21] and the Kjeldahl method [15]. In both methods, the total nitrogen in the sample is liberated at high temperature. In the Kjeldahl method, the nitrogen is released into a strong acid and the content is measured after neutralization and titration. In the Dumas method, the nitrogen is liberated in a gaseous form and is determined with a thermal conductivity detector, after removal of carbon dioxide and water aerosols. The Kjeldahl method was chosen as an example of this analytical principle in this study as it is still recognized as the official method for food protein determination by the AOAC International [14]. Following the nitrogen determination, crude protein content is calculated using a conversion factor. The original, and still frequently used, conversion factor 6.25 is based on an assumption that the general nitrogen content in food proteins is 16% and that all nitrogen in foods is protein-bound. These are, however, quite rough assumptions as the relative nitrogen content varies between amino acids and amino acid composition varies between food proteins [22]. In addition, a wide range of other compounds, such as nitrate, ammonia, urea, nucleic acids, free amino acids, chlorophylls and alkaloids contain nitrogen. These compounds are called non-protein nitrogen and their relative contents are often higher in vegetables than in foods of animal origin [5]. Throughout the years, it has been proven that the conversion factor of 6.25 in most cases overestimates the protein content and in order to adjust for these variations, several species-specific conversion factors have been suggested [6,7,16,22], making the conversion from nitrogen to protein more precise.

There are risks associated with calculating protein from nitrogen and the resulting overestimation of protein content. One is the possibility of food adulteration, as a high protein content often raises the economic value of a product [23]. There have been some cases where the producer in order to increase the apparent protein content [24], and subsequently the economic value of the food product have added non-protein nitrogen, such as melamine. This may compromise food safety for consumers and hence, it is important that such food adulteration is rendered impossible. Another risk is that the utilization potential and economic feasibility of “new” raw materials could be overestimated, as protein is one of the constituents with value-added potential in a product. Overestimation could thus give false premises for the establishment of new industries. For instance, the interest of increased industrial utilization of seaweeds has increased greatly the last decades. Several studies have presented a protein content of some red seaweed species of 30–45% [25,26], while when analyzed with amino acid analysis, it commonly ranges between 10% and 20% [11,27,28]. Such a difference could be crucial for the economy of small scale industries.

As expected, all of the Kjeldahl results using the traditional conversion factor were significantly higher, ranging from 44% to 71% higher, than the corresponding amino acid analysis results. More surprisingly, and except for the red algae, the species-specific conversion factors also gave significantly higher protein content than the amino acid analysis. One possible explanation may be that the concentration of some of the amino acids in the sample was reduced as a result of the hydrolysis process prior to the amino acid analysis and that the protein concentration calculated from this analysis was in fact underestimated. Another possible explanation could be that the “real” conversion factors for these species should in fact be even lower than the average values reported by Mariotti et al. [7]. Calculating conversion factors based on the results from this study gave factors of 4.9 for fish and shrimp and 4.7 for flours, respectively.

In the results of the amino acid analysis and the Kjeldahl analysis of the raw materials are shown. Both the traditional conversion factor of 6.25 and the respective species-specific conversion factors are presented. For fish, shrimp and flour, the species-specific factors used in these calculations were the average conversion factors suggested by Mariotti et al. [7], namely 5.6 for fish and shrimp and 5.4 for cereals. The conversion factor used for dulse is the factor suggested by Lourenco et al. [16] as an average for red algae, namely 4.59.

The third common analytical technique for protein analysis is spectrophotometry. Here, the principle is that functional groups or regions within the protein absorb light in the ultraviolet or visible range of the electromagnetic spectrum (200–800 nm). This absorbance is read and compared with known protein standards. Examples of such functional groups or regions are basic groups, aromatic groups, peptide bonds or aggregated proteins.

While both nitrogen analysis and amino acid analysis may be performed without any pre-treatment of the raw material, extraction of proteins is a prerequisite before submitting the material to spectrophotometric analysis. Also for protein extraction, the available methods are many. Most common protein extraction protocols are based on exposure of tissue to weak buffers or water, leading to collapse of cells with subsequent release of intracellular proteins as a response to the hypotonic shock that arises. This is very efficient for tissues containing cells without cell walls (animal cells), but not as efficient for cells with cell walls (plant cells). The latter being due to the cell walls protecting the cell against collapse [29]. In this study both protein sources of animal origin and protein sources of plant origin were included in order to evaluate these differences.

Of the commonest protein extraction methods, especially prior to electrophoresis, is the use of so-called Good’s buffers, a range of buffers first described in 1966 by Good et al. [8]. These buffers contain chemicals with zwitterionic properties, along with one or more detergents and are known to be highly compatible to biological analyses. They are highly water soluble, have low salt-effects and minimal interference with biological functions [10]. The main drawback of these protocols is that they involve several expensive chemicals and some of the chemicals are suspected to be health damaging. In this study, a mixture of HEPES (zwitterionic agent) and CHAPS (detergent) was chosen as an example of this principle.

Proteins are often divided into four main classes, based on their solubility properties. The four classes are albumins that are water-soluble, globulins that are soluble in weak ionic solutions, glutelins that are soluble in weak acidic or basic solutions and prolamines that are soluble in 70% ethanol. Most foods are complex matrices, probably holding several of these protein classes and combining several solutes would probably optimize the extraction yield. In Maehre et al. [9] it was shown that combining H₂O, 0.1 M NaOH and 3.5% NaCl at elevated temperature increased extraction yield compared to traditional extraction methods and this method was thus chosen as an example of a simpler protein extraction method in this study.

In , the extraction yields of the two different extraction methods are presented as protein content relative to the respective raw materials, calculated after amino acid analysis. As seen, extracting proteins using the HEPES/CHAPS protocol was quite ineffective, resulting in very low yields for all raw materials. Salt/alkaline extraction was shown to give significantly higher yields for all raw materials. Further, it was shown that the salt/alkaline protocol was very efficient for extracting proteins of animal origin, managing to extract more or less 100% of the protein. It was also quite efficient for extracting proteins from highly processed plant raw material (white flour), giving a yield of around 80%. The extraction yield was, however, lower in less processed and more complex plant materials, such as whole flour and dulse, the latter being comparable to a previous study [9].

One of the differences between the two chosen extraction methods was that salt/alkaline extraction was performed at 60 °C while HEPES/CHAPS was performed on ice and this could contribute to the difference in extraction yield. Extraction on ice probably protects the proteins against degradation, while heat treatment could possibly accelerate this. Thus, the extraction method should be chosen based on the purpose of further use. However, in this study the goal was merely to examine the differences in protein extraction yield between methods, and thus, protein degradation was not analyzed.

Following extraction, protein determination using two different spectrophotometric methods, the Bradford method [18] and a modified Lowry method [17], was tested and compared with amino acid analysis. In the Bradford method, Coomassie G-250 dye reacts with ionizable groups on the protein disrupting the proteins tertiary structure and exposing the hydrophobic pockets. This is followed by the dye binding to the hydrophobic amino acids forming stable complexes that can be read at 595 nm [3]. The modified Lowry method is a combination of the Biuret method, where copper ions react with the peptide bonds within the protein, and a reaction between Folin-Ciocalteu reagent and the ring structure on aromatic amino acids. The total reaction forms a stable, dark blue complex that can be read at 650–750 nm [3].

Character n (U+00F1) is encoded using UTF-8 as the two bytes 11000011 10110001 (0xC3 0xB1).

These two bytes are decoded using ISO 8859-1 as the two characters A±.

So, you are most likely using UTF-8 to encode the character as bytes, and ISO 8859-1 (Latin-1, as guessed by Sajmon) to decode the bytes as characters.

Letter A with overring

The letter A (a in lower case) represents various (although often very similar) sounds in several languages. It is a separate letter in Danish, Swedish, Norwegian, Finnish, North Frisian, Low Saxon, Walloon, Chamorro, Lule Sami, Pite Sami, Skolt Sami, Southern Sami, Ume Sami, and Greenlandic alphabets. Additionally, it is part of the alphabets used for some Alemannic and Austro-Bavarian dialects of German.^{[citation needed]}

Though A is derived from A by adding an overring, it is considered a separate letter. It developed as a form of semi-ligature of an A with a smaller o above it to denote a long and darker A, a process similar to how the umlaut mark developed from a small e written above certain letters.

The A-sound originally had the same origin as the long /aː/ sound in German Aal and Haar (Scandinavian al, har, English eel, hair).

Historically, the a derives from the Old Norse long /aː/ vowel (spelled with the letter a), but over time, it developed to an [ɔː] sound in most Scandinavian language varieties (in Swedish and Norwegian, it has eventually reached the pronunciation [oː]). Medieval writing often used doubled letters for long vowels, and the vowel continued to be written Aa.

In Old Swedish the use of the ligature AE and of O (originally also a variant of the ligature OE) that represented the sounds [ae] and [o] respectively were gradually replaced by new letters. Instead of using ligatures, a minuscule (that is, lower-case) E was placed above the letters A and O to create new graphemes. They later evolved into the modern letters A and O, where the E was simplified into the two dots now referred to as umlaut. A similar process was used to construct a new grapheme where an "aa" had previously been used. A minuscule O was placed on top of an A to create a new letter. It was first used in print in the Gustav Vasa Bible that was published in 1541 and replaced Aa in the 16th century.^[1]

In an attempt to modernize the orthography, linguists tried to introduce the A to Danish and Norwegian writing in the 19th century. Most people felt no need for the new letter, although the letter group Aa had already been pronounced like A for centuries in Denmark and Norway. Aa was usually treated as a single letter, spoken like the present A when spelling out names or words. Orthography reforms making A official were carried out in Norway in 1917 and in Denmark in 1948. According to Jorgen Norby Jensen, senior consultant at Dansk Sprognaevn, the cause for the change in Denmark was a combination of anti-German and pro-Nordic sentiment.^[2] Danish had been the only language apart from German and Luxembourgish to use capitalized nouns in the last decades, but abolished them at the same occasion.

In a few names of Danish cities or towns, the old spelling has been retained as an option due to local resistance, e.g. Aalborg and Aabenraa; however, Alborg and Abenra are the spellings recommended by the Danish Language Board.^[3] Between 1948 and 2010, the city of Aarhus was officially spelled Arhus. However, the city has changed to the Aa spelling starting 2011, in a controversial decision citing internationalization and web compatibility advantages.

Icelandic and Faroese are the only North Germanic languages not to use the a. The Old Norse letter a is retained, but the sound it now expresses is a diphthong, pronounced [au] in Icelandic and [ɔa] in Faroese. The short variation of Faroese a is pronounced [ɔ], though.

In some place names, the old Aa spelling dominates, more often in Denmark than in Norway (where it has been abolished in official use since 1917). Locals of Aalborg and Aabenraa resist the A, whereas Alesund is rarely seen with Aa spelling. Official rules allow both forms in the most common cases, but A is always correct. A as a word means "small river" in Danish, Swedish, and Norwegian and can be found in place names.

Before 1917, when spelling with the double A was common, some Norwegian place names contained three or four consecutive A letters: for instance Haaa (now Haa, a river) and Blaaaasen (Blaasen, 'the blue ("bla") ridge ("as")').

In family names, the bearer of the name uses Aa or A according to their choice, but since family names are inherited they are resistant to change and the traditional Aa style is often kept. For instance, the last name Aagaard is much more common than Agard. The surname Aa is always spelled with double A, never with the single a. However, given names - which are less commonly inherited - have largely changed to the use of the A. For instance, in Norway more than 12,000 male citizens spell their name Hakon, while only around 2,500 are named Haakon.

Company names are sometimes spelled with the double A by choice, usually in order to convey an impression of old-fashionedness or traditionality. The double A, representing a single sound, is usually kept in initials e.g. for people whose first, middle, and/or last name begins with the double A. Accordingly, a man named "Hans Aagard Hauge" would spell his initials "H. Aa. H." (not "H. A. H." nor "H. A. H."), while a woman named Aase Vestergaard would spell her initials "Aa. V." (not "A. V." nor "A. V.").

Correct alphabetization in Danish and Norwegian places A as the last letter in the alphabet, the sequence being AE, O, A. This is also true for the alternative spelling "Aa". Unless manually corrected, sorting algorithms of programs localised for Danish or Norwegian will place e.g., Aaron after Zorro.

In Danish the correct sorting of aa depends on pronunciation: If the sound is pronounced as one sound it is sorted as A regardless of the sound is 'a' or 'a'; thus, for example, the German city Aachen is listed under A, as well as the Danish city Aabenraa. (This is §3 in the Danish Retskrivningsreglerne.)

In the Swedish and Finnish alphabets, A is sorted after Z, as the third letter from the end, the sequence being A, A, O. This is easiest to remember across the Nordic languages, that Danish and Norwegian follow Z first with E-mutated letters AE and O and then the symbol with a one-stroke diacritic A. Swedish and Finnish follow Z with a one-stroke diacritic A and then a two-stroke (or two-dot) diacritic A, O. A combined Nordic sorting mnemonic is AE, O, A, A, O.

Alternative spellings of the Scandinavian A have become a concern because of globalization, and particularly because of the popularization of the World Wide Web. This is to a large extent due to the fact that prior to the creation of IDNA system around 2005, internet domains containing Scandinavian letters were not recognized by the DNS system, and anyway do not feature on keyboards adapted for other languages. While it is recommended to keep the A intact wherever possible, the next best thing is to use the older, double A spelling (e.g. "www.raade.com" instead of "www.rade.com"). This is because, as previously discussed, the A/Aa indicates a separate sound. If the A is represented as a common A without the overring (e.g. "www.rade.com") there is no indication that the A is supposed to represent another sound entirely. Even so, representing the A as just an A is particularly common in Sweden, as compared to Norway and Denmark, because the spelling Aa has no traditional use there.

Because the Finnish alphabet is derived from the Swedish alphabet, A is carried over, but it has no native Finnish use and is treated as in Swedish. Its usage is limited to loanwords and names of Swedish, Danish or Norwegian origin. In Finland there are many Swedish-speaking as well as many Finnish-speaking people with Swedish surnames, and many Swedish surnames include A. In addition, there are many geographical places in the Finnish coastal areas that have a in their Swedish names, such as Krako and Langnas. The Finnish name for A is ruotsalainen O ("Swedish O"), and is pronounced identically to O, which has the value [o̞].

It is not advised to substitute aa for a in Finnish, as aa is already a common letter combination with the value [aː].

In Emilian-Romagnol, a is used to represent the open-mid back unrounded vowel [ʌ], e.g. Modenese dialect amm, danna [ˈʌmː], [ˈdʌnːa] "man, woman";

e.g. Bolognese dialect Bulaggna, dapp [buˈlʌɲːa] [ˈdʌpː] "Bologna, later".

A was introduced to some eastern local variants of Walloon at the beginning of the 16th century and initially noted the same sound as in Danish. Its use quickly spread to all eastern dialects, but the cultural influence Liege and covered three sounds, a long open o, a long close o or a long a, depending on the local varieties. The use of a single a letter to cover such pronunciations has been embraced by the new pan-Walloon orthography, with one orthography for words regardless of the local phonetic variations. The Walloon use of A became the most popular use outside a Scandinavian language, even being used in the International Phonetic Alphabet drafted by Otto Jespersen.

In standardized writings outside the Liege area, words containing a are written with uh, a or o. For example, the word majhon (house), in the standardized orthography is spelled mojo, mahon, mohone, maujon in dialectal writings.

The Istro-Romanian alphabet is based on the standard Romanian alphabet with three additional letters used to mark sounds specific only to this language: a, l and n.

A and a are also used in the practical orthography of Chamorro, a language indigenous to the people of Northern Mariana Islands and Guam. The Chamorro name for Guam is Guahan, and its capital is called Hagatna.

In Greenlandic, a is not used in native words, but is used in several loanwords from Danish, such as bandoptageri (Danish bandoptager) 'tape recorder'. Like in Danish, a is sorted last in the alphabet.

The letter "A" (U+00C5) is also used throughout the world as the international symbol for the non-SI unit angstrom, a physical unit of length named after the Swedish physicist Anders Jonas Angstrom. It is always upper case in this context (symbols for units named after persons are generally upper-case). The angstrom is a unit of length equal to 10−10 m (one ten-billionth of a meter) or 0.1 nm.

Unicode also has encoded U+212B Å ANGSTROM SIGN. However, that is canonically equivalent to the ordinary letter A. The duplicate encoding at U+212B is due to round-trip mapping compatibility with an East-Asian character encoding, but is otherwise not to be used.^[4]

The logo of the Major League Baseball team known as the Los Angeles Angels is a capital "A" with a halo. Due to the resemblance, some Angels fans stylize the name as "Angels".

The logo of the Stargate series similarly features a stylized A with a circle above it, making it resemble an A as in Stargate; in Norwegian, gate means "riddle".

Cirque du Soleil's Kooza production uses this character in its logo, although it is pronounced by the main singer as a regular "a".

British producer and singer Lapsley uses it in her stage name.