acidic

This Cuisinart coffee maker steeps cold brew in a fraction of the time and it’s $50 off at Best Buy

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Cold brew coffee has a smoother and sweeter taste than traditionally brewed coffee. Heat produces oils that bring out acidic flavors in coffee, so therefore, lack of heat does not. (Science.)

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Right now, you can snag the Cuisinart Automatic Cold Brew Coffee Maker for $49.99 at Best Buy. You’ll be saving $50.

Like traditional cold brewers, the Cuisinart saturates coffee grounds in cold water to avoid bringing out the oils that create the acidic taste. Unlike traditional methods, this coffee maker uses unique spin technology to circulate coffee through water to create maximum flavor extraction in a fraction of the time. 

You have three flavor strength options to create your perfect cup of cold brew. Plus, your coffee can be refrigerated in the seven-cup carafe for up to two weeks.

Get brewing with the Cuisinart Automatic Cold Brew Coffee Maker for $50 off at Best Buy.

Electronic musician Acidic Base is generating buzz with his debut album. He's also a Naperville 12-year-old.

Siddharth Goswami is a typical eighth-grader at Crone Middle School in Naperville, a member of the school orchestra whose favorite subject is science.

But 12-year-old Sid – as he introduces himself – also is known as Acidic Base, the artist who mixes melody, harmony, rhythm and dynamics to create an electronic sound that has been astonishing music critics since his debut album was released two months ago.

“Purple Skies,” named after its title track, is a compilation of seven songs in the trance genre of electronic music, all of which the Naperville boy wrote and produced. Other tunes include “Blurred,” “Borealis,” “Chernobyl,” “Halcyon,” “Mountain Face” and “Omnidirectional Hyperjet.”

“Each song has a different story,” Sid said.

His favorite is “Borealis,” partly because of the 50 hours he spent honing the tune.

“I spent hours on that,” he said. “It’s very full of a style I really like.”

Sid said not only does it have a “driving beat that’s danceable,” it’s a great song if a person just wants to “chill.”

“Chernobyl,” the longest song at nearly 8.5 minutes, paints the musical story of the Ukrainian nuclear power plant meltdown. “At the end, I convey the radioactivity,” he said.

While 1986 incident happened long before he was born, Sid said he learned about the disaster from published reports. “I like reading about events in history,” he said.

A precocious child by nature – he was the youngest docent the Volo Bog in Lake County ever had – Sid said he was first introduced the genre of electronic music while flipping through a friend’s playlist at a party two years ago.

“It’s something different from what I’ve experienced,” he said.

That kindled his interest in creating music of his own.

Sid’s fascination with music started when he was 6 years old, his father Sujit Goswami said. The boy wanted to learn to play an instrument so his parents enrolled him in piano lessons at a local studio.

“Musically, I think he is gifted,” Goswami said of how quickly Sid learned to play songs on the piano.

A fan of Elton John and Billy Joel, Sid proved his musical prowess, often performing a piece from both artists after hearing it only once, his father said.

Wanting to push his piano skills more, Sid started taking classical piano classes at the Music Institute of Chicago and focused on aspects of chord progression and music theory.

When the opportunity arose to play with the school orchestra, the boy selected the violin.

“Then I went to the guitar,” Sid said.

He’s since learned to play the electric guitar, bass guitar and drums.

Now Sid combines knowledge of music theory with his ability to play multiple instruments to create electronic music on a computer and keyboard in his makeshift studio on a table off the kitchen in his family’s home.

To finalize his songs before releasing them online, Sid secured time at professional studio. He said his home system isn’t equipped to record the sound when he’s laying down a track on his electric guitar.

The pre-teen said he draws inspiration from artists like Eric Prydz and Deadmau5, from whom he’s taken an online master class in electronic music production.

Released in December, “Purple Skies” is creating buzz among music blogs.

Filmmaker and blogger Glenn Rodriguez said he was amazed to learn Sid is 12 years old.

“I mean, I know creating music is easier than ever now with all the technology and it is more accessible than ever,” said Rodriguez, who does a “Songs For The Moment” podcast.

But Rodriguez said he’s surprised because how “well-crafted the music was. It’s amazing stuff.”

In his review, Rodriguez said his favorite track was “Chernobyl” because it “has some killer synth leads and hard hitting drums.”

“I love the mix to this as well. It’s an eclectic sounding track. Plenty of movement between tempos,” the review noted.

Sid says he’s pleased with the reviews. “Most say it’s good,” he said. “I want helpful criticism.

“Some people say it is fluid in terms of style and what you can do with it,” he added.

The process of composing, Sid said, starts when either a chord progression or melody pops in his head. “Most of the spark comes randomly,” he said.

Sid forms the melody and harmony on the piano in the family’s front room before bringing his musical concept to the computer, where he adds the rhythm.

Usually the name comes after the song is written.

As far as his nom de plume Acidic Base, Sid said that came to him “pretty abstractly” when he was talking with a friend about chemistry.

Sid already has started on his next album project, though he’s not sure where it will lead.

Composing music that tells a story or one that can take the user through a theme is his passion, he said.

“I see myself working more on complex and dynamic themes in some of my next few releases,” Sid said.

subaker@tribpub.com

Twitter @SbakerSun

Catalytic preparation of levulinic acid from cellobiose via Brønsted-Lewis acidic ionic liquids functional catalysts

The acidity of ILs

The Brønsted acidity of three kinds ILs was determined by UV-visible spectroscopy. The acidity of ILs was calculated by the Hammett equation H0 = pK(I)aq + log([I]/[IH]+), which indirectly reflects the relationship of acidity and activity. As shown in Fig. 1, for ILs with the same chloride anion structure, the acidity of the ILs increased in order: d(imidazolyl) > c(pyridyl) > b(triethylamine).

Effects of catalysts on the LA yield

ILs were considered as desirable catalyst and their structures were changed by adjusting the cation and anion in order to obtain the desired properties. According to Ren’s report31, anion played a key role in the process of biomass conversion to LA, such as HSO4, H2PO4, CH3SO3, Cl−. Zuo et al.19 found that Cl− could better combine with the hydroxyl of cellulose, increasing the breakage of the hydrogen bonding network of cellulose to break the extensive and facilitate its dissolution. However, the CP-SO3H catalyst used by Zuo et al. was easily deactivated under hydrothermal conditions. Therefore, in this study, different kinds of Brønsted-Lewis acidic ILs were used to catalyze the conversion of cellobiose to LA. As shown in the Table 1, [HO3S-(CH2)3-mim]Cl, [HO3S-(CH2)3-NEt3]Cl, [HO3S-(CH2)3-py]Cl combined three kinds of metal salts, ZnCl2, FeCl3, and CrCl3 were used in this study. When the ILs had the same cation structure, their acidity was affected by the metal chloride, the acidity of ILs increased in order: CrCl3 < ZnCl2 < FeCl3. The acidity of the Brønsted acidic ILs increased in order: [HO3S-(CH2)3-NEt3]Cl < [HO3S-(CH2)3-py]Cl < [HO3S-(CH2)3-mim]Cl. Simultaneously, compared with [HO3S-(CH2)3-py]Cl and [HO3S-(CH2)3-NEt3]Cl, [HO3S-(CH2)3-mim]Cl had good catalytic performance. When [HO3S-(CH2)3-mim]Cl-FeCl3 (x = 0.60) was tested, the LA yield was 67.51% at 180 °C for 10 h. In the presence of Lewis acidic CrCl3, Brønsted-Lewis acidic ILs had poor catalytic effect. This was because CrCl3 could hinder the formation of LA32. Consequently, the stronger catalytic activity of these ILs, the higher yield of LA was obtained, which indicated that the acidity of ILs played key role in the process of catalyzing the conversion cellobiose to LA. This phenomenon was caused by the reason that the stronger acidic. The more would promote the protonation of glycoside oxygen. Simultaneously, HCl and H3PW12O40 were also used as reference acid catalysts for conversion of cellobiose to LA, and gave 55.77% and 60.94% yields of LA, respectively. Compared to [HO3S-(CH2)3-mim]Cl-FeCl3 (x = 0.60), HCl and H3PW12O40 had poor catalytic effect.

A series of complicated reactions were included in the conversion of cellobiose to LA, which involved depolymerization, dehydration, isomerized and so on. The conversion of cellobiose to LA was divided into three intermediate reaction steps. As shown in Fig. 2, the cellobiose was depolymerized into glucose at first and then glucose was converted to HMF, which further was hydrolyzed to LA. In the first step, Cl− was attached to the hydroxyl groups of cellobiose by hydrogen-bond interaction, and then cellobiose was adsorbed onto the catalyst. Thereby β-glycoside bonds were broken down by protonation. In the second step, there were two ways to produce HMF from glucose, one was that HMF was directly produced from glucose, another was that glucose isomerized to fructose and then to produce HMF from fructose. According to the literature33, glucose isomerized to fructose was the control step of the whole reaction, and Lewis acidic could promote this process. In the third step, HMF was directly hydrolyzed to produce LA under the action of H+. Table 1 and Fig. 2 shown that apart from acidity factor, the synergistic catalytic of Brønsted-Lewis not only could break the glycoside bond of cellobiose, but also could provide enough acid sites to promote the conversion of glucose to LA. At the same time, since H3PW12O40 included metal W and P elements which could provide Lewis acidic, and H+ which could provide Brønsted acidic, so LA also had good yield. However, due to H3PW12O40 lack Cl−, the first step in the conversion of cellobiose to LA could be affected, so its catalytic effect was lower than that of most Brønsted-Lewis acidic ILs.

Figure 2

Mechanism of cellobiose conversion to LA.

Effects of reaction conditions on the LA yield

Table 2 shows the effect of different reaction conditions on the conversion of cellobiose to LA. The reaction temperature was very important for preparing LA from cellobiose. With increasing of reaction temperature from 160 °C to 180 °C (Entry 1, 2, 3), the yield of LA increased from 51.0% to 67.51%, the yield of glucose and HMF decreased from 12.74% to 10.85% and from 1.47% to 0%, respectively. However, when the temperature exceeded 180 °C (Entry 4), the yield of LA declined to 59.72%. This was because that as the temperature increased, the viscosity of the reaction system would fall, the mass transfer rate would increase, and the reaction rate also would increase, which was beneficial to the generation of LA28. However, glucose and HMF were easily polymerized into by-products when a high temperature was employed34. Therefore the yield of LA decreased as the temperature was more than 180 °C.

Table 2 The yield of LA using different reaction conditions.

Reaction time also was an important factor which affected conversion of cellobiose. With the extension of reaction time (Entry 5, 6), the yield of the LA arranged from 50.88% to 56.43%, but the yield of glucose and HMF decreased correspondingly. When reaction time reached 10 h, the maximum LA yield of 67.51% was achieved (Entry 3). However, when the time exceeded 10 h (Entry 7), the yield of LA declined to 58.73%, the yield of glucose declined to 10.14% and the yield of HMF was still 0%. This might because the cellobiose could not be fully reacted in a short reaction time, and LA was degraded into other products when reaction time was too long.

Table 2 also shows the effect of the catalyst dosage on LA yield. When the dosage of ILs increased from 0.32 mmol to 0.62 mmol (Entry 8, 3), the yield of LA increased from 45.01% to 67.51% obvious. This increased could be attributed to an increase in the availability of the number of active sites. Notably, the yield of LA decreased from 67.51% to 63.50% when more than 0.62 mmol of ILs were added (Entry 9, 10), which suggested that excessive amount of catalyst would accelerate the decomposition rate of LA, thus leading to the decrease of LA yield. It was implied that sufficient catalytic sites were available for conversion of cellobiose to LA at the experimental conditions. Meanwhile, with the increase of catalytic sites, the degradation rate of cellobiose increased, so the glucose yield increased slightly.

Recycling of IL

ILs were an environmentally-friendly catalyst due to their respectability and reusability. The IL recycled after five times and fresh IL was investigated by IR spectra (Fig. 3), the bands of 1445 cm−1 and 1039 cm−1 represented asymmetric stretching vibration and symmetric stretching vibration of sulfonic acid, respectively. Bands of 3417 cm−1, 3153 cm−1 and 3095 cm−1 represented hydrogen bond of sulfonic acid. We could see that the band around 3340 cm−1 had obviously changes, corresponding to H+ of sulfonic acid was lost in the catalytic process. Through the 1H NMR spectra of fresh IL and IL recycled after five times was detected, as shown in Fig. 4. From Fig. 4, it could be seen that the IL catalyst remained stable under the reaction conditions and did not decompose to the corresponding zwitterion. As shown in Table 3, the yield of LA slightly declined from 67.51% to 62.57% after [HO3S-(CH2)3-mim]Cl-FeCl3 (x = 0.60) was used repeatedly five times. Thus, Brønsted-Lewis acidic ILs were a stable, highly reproducible catalyst.

Figure 3

IR spectrum of IL. (a) IL recycled after five times and (b) fresh IL, [HSO3-(CH2)3-mim]Cl-FeCl3 (x = 0.60).

Figure 4

Typical 1H NMR spectra. (a) fresh IL and (b) IL recycled after five times, [HSO3-(CH2)3-mim]Cl-FeCl3 (x = 0.60).

Table 3 Effect of different reusability of catalyst on LA yield.Separating of LA

LA product could be easily separated by extraction with MIBK. Through comparison 1HNMR and IR of LA standard and LA product were detected, as shown in Figs 5 and 6. From Fig. 5, two bands at 3180 cm−1 and 2930 cm−1 changed noticeably, corresponding to O-H and C-H stretching vibrations, respectively. This might be caused by the reaction of aldehydes and formic acid. In comparison, the band at 1710 cm−1 didn’t change very much, which was attributed to C=O stretching vibration. From Fig. 6, we could see that the characteristic peaks of the recovered LA and LA product were similar. So Figs 5 and 6 confirmed that LA could be separated in this reaction system.

Figure 5

IR spectrum of LA. (a) LA standard and (b) LA product.

Figure 6

Typical 1H NMR spectra. (a) LA standard and (b) LA product.

Characterization of solid residues

In the process of LA production, and a lot of humins would be produced and the humins could be characterized by IR spectra (see Supplementary Fig. S3). The absorption peak at 3400 cm−1 was attributed to O-H stretching vibrations. 2924 cm−1, 1694 cm−1 and 1621 cm−1 corresponding to C-H, C=O, C=C stretching vibrations, respectively. The absorption peaks at the 1000–1500 cm−1, which were attributed to C-O stretching and O-H bending vibrations. The absorption peaks at 745–880 cm−1, which were attributed to aromatic C-H out-of-plane bending vibrations. These were similar to the literature record29.

To further reveal the difference between solid residues and cellobiose, we had performed SEM characterization. Figure 7a indicated that the particle size of cellobiose lower magnification with a distinctly massive structure, and cellobiose surface also had a sporadic block structure under higher magnification as shown in Fig. 7b. After the reaction, the original block structure was decomposed leaving a small agglomerate particle as shown in Fig. 7c,d at higher magnification exhibited independent spherical particle. According to Ren’s report31, characteristic morphology of solid humins substances was spherical particle at higher magnification. It was indicated that the solid residues were humins under the reaction system.

Figure 7

SEM images of cellobiose and solid residues. (a,b) cellobiose and (c,d) solid residues.

The changed in the weight of the cellobiose and solid residues as a function of temperature was shown in Fig. 8. It was clearly to see that the main decomposition temperature of cellobiose in the range of 245–334 °C. After reaction, the cellobiose peak disappeared in the range of 245–334 °C. Simultaneously, a broader peak appeared between 341 °C and 499 °C. According to literature reports35, the appeared of characteristic peak in the range of 341–499 °C was solid humins. It was indicated that the thermal stability of solid humins substances was excellent, mainly because of increased heat resistance of humins after further dehydration in the conversion process.

Figure 8

TG-DTG curves of cellobiose and solid residues.