جستجوی مقالات مرتبط با کلیدواژه « کافئین » در نشریات گروه « صنایع غذایی »

In this study, chitosan-coated nanoliposomes in ratios of 9-1, 8-2, 7-3 and 6-4 lecithin-cholesterol, were prepared using thin-film hydration method, as a practical delivery system for encapsulation of caffeine. Then, the particle size and zeta potential were measured to determine the characteristics of the produced particles. Average particle size (average hydrodynamic diameter) and particle size distribution for different lecithin-cholesterol ratios were in the range of 135.5-533.5 nm and 0.31-0.41, respectively. Zeta potential values were also obtained in the range of +40.96 to +50.5. After determining the encapsulation efficiency, FTIR method was used to investigate possible reactions between caffeine and nanoliposome wall materials. The morphology of chitosome with 9-1 ratio of lecithin-cholesterol loaded with caffeine, was shown by scanning electron microscopy (SEM). The stability of the chitosomal sample with a ratio of 1-9 lecithin-cholesterol was evaluated through visual observation of precipitation formation and calculation of the amount of release of encapsulated caffeine during 60 days of storage at ambient temperature. The results obtained in this research showed that nanochitosomes are an efficient system in maintaining and releasing caffeine.

Date seed is considered as one of the most important wastes in the date processing industry which despite its high nutritional value, it is usually disposed of. This results in environmental contamination that require high cost to resolve. On the other hand, waste valorization in the food industry is important both in terms of environmental and economic benefits. Studies indicated that date seeds have a high nutritional value and could be considered as a good source of bioactive compounds (Platat, Habib, AL Maqbali, Jaber, & Ibrahim, 2014). The amount of dietary fiber in different types of date seeds varies between 20 to 80% w/w (Al-Juhaimi et al., 2018). Date seeds also contain 5.9-9.9% w/w protein (Bouaziz et al., 2008) and 5-13 w/w oil (Nehdi et al., 2010). The antioxidant properties of date seeds are also derived from its components such as vitamin E, beta-carotene and phenolic compounds. Thus, date seeds have the potential to be used as an ingredient in other foods, directly or indirectly (Al-Farsi et al., 2007). One of the relatively inexpensive ways to added value on date seed is to prepare a beverage from roasted date seed powder. The roasting process enhances the flavor of the brew, increases the shelf life of the product. It is hypothesized that roasting can lead to an alternative product for those who want to enjoy a somewhat coffee-like brew without caffeine (Fikry et al., 2019; Ghnimi, Almansoori, Jobe, Hassan, & Kamal, 2015). However, as it has been reported in terms of coffee, method of brewing and bean varieties can make a difference in the antioxidant properties of the final product (Vignoli, Bassoli, & Benassi, 2011). As a result, in this study, the effect of variety and method of preparation on the antioxidant properties of beverage obtained from roasted date seeds was investigated, which has not been mentioned so far. For this purpose, two types of date seed (Shahani and Mazafati) were used to prepare espresso, boiled and filtered brews and the results were compared with respective arabica coffee brews

Arabica coffee (Coffea arabica) and two types of Shahani and Mazafati dates were purchased from local stores in Mashhad, Iran. Three types of coffee brews including espresso, boiled and filtered brew were prepared. In this study, the antioxidant properties, phenolic and flavonoid content, caffeine, melanoidin, color parameters and pH of brews (espresso, boiled and filtered) were studied.

The phenolic content in Mazafati and Shahani and arabica coffee brews were in the range of 37-102, 41-194 and 52-328 mg/100 mL, respectively. The method of preparation also has a significant effect on the extraction of phenolic compounds, as the content of phenolic compounds in coffee increased from 52.94 prepared via the filter method to 328.33 mg in 100 ml of espresso coffee. In the present study, the total flavonoid content in Mazafati, Shahani and arabica coffee brews were 11-30, 14-68 and 32-200 mg/100 ml of beverage, respectively. The decrease in the content of phenolic as well as flavonoid content in date seed beverages can be attributed to both the lower amount of these compounds in the powders and the lower rate of their extraction. The results of Olechno et al. (2020) indicate a significant effect of the preparation method on various phenolic compounds content in coffee. The reducing power of Fe+3 in beverages obtained from Shahani date seed was almost twice that of found in Mazafati date seed. However, in all beverages, the highest reducing power of Fe+3 was found in espresso coffee (32.13 mmol Fe+2/L). Besides, the free radical scavenging power of DPPH in date seed brews were close to arabica coffee as the values in the date seeds of Shahani, Mazafati and arabica coffee (depending on the type of beverage) varied in the range of 2.66-8.79, 2.79-14.6 and 2.13-13.95 mmol Trolox/L, respectively. The results show a negligible amount of caffeine in the date seed brews as the amount of caffeine in these samples, regardless of the method of preparation, were 0.26-2.82 and 0.3-3.1 mg/100 ml, respectively. While caffeine content in coffee (regardless of preparation method) ranged from 36.90 to 75.24 mg per 100 ml of brew. The amount of melanoidins in Arabica coffee was significantly higher than those found in date seeds. This difference in melanoidins level can be seen in a variety of preparation methods. Espresso and boiled coffee brews had the highest amount of melanoidins in an insignificant manner (p>0.05). This trend was also observed in brews prepared from date seeds. The method of preparation had a significant effect on pH (p<0.05). The pH value in brews prepared from arabica coffee and Shahani date seed were as follows: filter> espresso> boiled and in Mazafati brews was as follows: espresso> filtered> boiled. Regarding color parameters, Shahani and Mazafati date seed brews were almost similar and indicated more L* than coffee brew. This proved that date seed brews are lighter than coffee brews. In general, the highest amount of L* (82.35) was observed in Shahani date seed brew prepared by filter method and the lowest amount (20.02) was observed in arabica coffee prepared by espresso method. Parameter b* indicates the range of yellow (+) to blue (-) and its value in beverages prepared from Shahani and Mazafati brews (27-37) was more than coffee drinks (17-25).

In general, although roasted date seeds brews had less antioxidant properties than arabica coffee brews, the results showed the presence of relatively moderate amounts of these compounds in date seed beverages provide high potential of use this drink in the future as healthy beverage. In addition, due to the absence of caffeine, these brews can be considered as a good option for people who are sensitive to caffeine.

In this research hydrogel-based colloidosome with shell of CaCO3 microparticles was used in order to encapsulate caffeine as a model flavor compound. When the CaCO3 particles were dispersed in sunflower oil and then water in oil emulsion was prepared, with adding D-gluconic acid δ-lactone, water droplets containing alginate slowly gelate with outer layer of CaCO3 particles in micrometer hydrogels in the size of a few 10 µm without coagulation. CaCO3 microparticles act as both cross-linker for the alginate and stabilizer of water in oil emulsion. After leaving for 48 h, the hydrogel colloidosomes sank to the bottom of the container due to gravity. The results of infrared spectroscopy showed that indicative peaks of caffeine functional groups appeared in the loaded colloidosome sample spectrum and shifted its position. The results of calorimetric tests showed that the difference between the melting point of colloidosome samples with varying amounts of calcium carbonate microparticles in their formulas are linked. The results of the X-ray diffraction test showed a change in the crystalline degree of caffeine. After 5 h, the colloidosome sample, continued the caffeine release in water up to 55% maximally, while using mouth conditions for this sample, release of the loaded caffeine increased 33%. Generally, the results of instrumental analysis and release test showed that caffeine in the hydrogel colloidosome was well encapsulated within the alginate hydrogel network and have proper release under simulated oral condition.

Coffee is the most important and popular beverage in the world. The main differences between coffee and other beverages like tea is the variety of applied brewing techniques. Coffee is a complex chemical mixture of compounds including, caffeine, as a natural alkaloid. Besides its beneficial effect including enhancement in mental activity and alertness as well as improving the cognitive functioning, caffeine indicated adverse effects such as headache and anxiety when it is consumed in higher quantity. In terms of chemical extraction, it can be also considered as an interference when analyzing other pollutants, therefore, its removal from extract is of great interest. Therefore, the present study was designated to investigate the caffeine content of 18 various coffee-related products. Furthermore, the effect of two extraction techniques (QuEChERS and conventional) on caffeine removal from coffee extract was investigated.
 
Coffee brews including classical (boiled, French, moka and filtered coffees) and commercial brews (various types of espresso as well as instant and iced coffees) were prepared using Robusta, Arabica coffee or commercial powders. In conventional extraction approach, a 2.5 mL of coffee sample was treated with 0.1 mL each of Carrez solutions I and II to clarify the sample. The total volume was brought to 50 mL by the addition of 10% methanol (v/v). After centrifugation, the supernatant was filtered and analyzed using high-performance liquid chromatography coupled with a diode array detector (HPLC-DAD) at 273 nm. In QuECHERS approach, the effect of extraction solvent (acetonitrile and ethyl acetate) and sorbents (primary and secondary amines and, octadecyl silane) on caffeine removal was investigated and was compared to conventional approach as reference method. The extraction and clean-up were accomplished by two types of solvents and sorbents in the presence of sodium chloride and magnesium sulfate. Finally, caffeine was determined using HPLC-DAD at 273 nm.
 
According to the results, the two coffee varieties (Arabica and Robusta) were clearly separated by their caffeine contents as Robusta presented higher values in all classical brews. Among the classical brewing techniques, the coffee with the highest content of caffeine was moka brewed from roasted Robusta coffee, with a mean value of 1044 ± 26 mg/L. The caffeine content was also determined per serving (cup size) to determine the actual content received by consumers. Accordingly, among traditional brews the most caffeine-rich coffee was espresso type pod coffee, with a mean value of 1371 ± 16 mg/L, equivalent to 56 ± 0.6 mg/40 mL of serving size. The lowest mean caffeine content (13.4 mg / 240 mL) was found in iced coffee. With regards to caffeine extraction, with recovery of 101%, the conventional method was the most efficient approach for caffeine determination. Caffeine significantly reduced (around 20% compare to conventional approach) when QuEChERS was used as extraction technique which could be valuable for analysis of pesticides, which are usually present in small quantities in food samples like coffee. In general, the use of acetonitrile as well as the simultaneous application of PSA and C18 resulted in a significant decrease in caffeine content of Robusta coffee extract.
Here, different coffee brews were assessed and compared for their caffeine content (mg/mL and mg/serving). Technical differences like coffee varieties, coffee/water ratio or method of brewing (pressurized, fusion, filtering, etc) led to coffee brews with different caffeine profiles. Interestingly, despite the high concentration of caffeine in espresso types brews, they provided moderate coffee in terms of caffeine content per cup. On the other hand, classical methods in particular boiled, French and filtered Robusta coffee were rich in terms of caffeine per cup. When studying caffeine extraction, the efficiency of conventional method was significantly superior to QuEChERS approach as caffeine significantly reduced when QuEChERS was used as extraction method.

Polyphenols by antioxidant properties in tea are responsible for the health. One of the major alkaloids witch found in tea leaves is caffeine. The purpose of this study was to compare the total polyphenols and caffeine contents in the varieties of green and black tea and instant types of them، which provided from tea garden of Lahijan from north of Iran. Caffeine contents of tea samples were extracted with chloroform as a solvent. Results showed that the average amount of total polyphenols within the range of 4. 8027 to 21. 6510 (g/100g dm)، decrease in green tea، instant black tea and black tea، respectively and comparison of the results showed that although there are differences between the obtained values، but the difference of the total amount of polyphenols in green tea and instant black tea is not significant (p<0/05). According to the results the average amount of caffeine decrease in the instant black tea، instant green tea، black tea and green tea، respectively and the difference of the amount of caffeine (2. 2026 to 5. 3232 g/100g dm)، in samples is significant (P<0/05).