Amarthya Benigna Achmadi’s research while affiliated with Bandung Institute of Technology and other places

Coffee consumption could provide various benefits for human health, but also could contribute to several health problems. The growing trend of coffee consumption has created a rising demand for decaffeinated coffee that is safe for consumers with low caffeine tolerance. Decaffeination process, however, can result in the alteration of several properties of coffee which affect overall coffee taste. This review discussed current decaffeination methods such as water decaffeination, solvent decaffeination, supercritical decaffeination, and biodecaffeination which includes their mechanisms, benefits, and drawbacks as well as their effect in the physicochemical and sensory characteristics of coffee. Solvent decaffeination has showed potential improvements in the future such as the incorporation of membrane and ultrasonic technology. In addition, the mathematical model for caffeine diffusion has been arranged according to Fick’s second law of diffusion, based upon spherical and rectangular coordinates with several assumptions. Further research should be aimed to maintain the properties of coffee after decaffeination process. Furthermore, utilizing new solvents that are safe and non-toxic will potentially be favorable research in the development of decaffeination methods in the future.

The high productivity of mangosteen and its utilization in various industries produce the mangosteen peel as a waste of the process. Mangosteen peel as a lignocellulose‐based material has great potential to be utilized as a biosorbent, especially in the separation process of wastewater pollutants. Previous studies on mangosteen peel biosorbent are limited to the adsorption of heavy metal ions, dyes, and CO2 separation process. These studies show that the separation efficiency can reach above 90%, which indicates the potential to be expanded for the usage of other compounds as the adsorbate. The gradual diffusion process of adsorbate molecules into biosorbent pores depends specifically on the suitability of the materials and the operating conditions of the adsorption process. Materials suitability can be modified by the biosorbent pretreatment process to enhance its adsorption capacity. The mangosteen peel biosorbent, which still performs well in the adsorption process even after being regenerated for a few cycles, is an added value for its potential to be utilized as a biosorbent in various applications because it can reduce costs and process waste; also expand the possibility to reuse the desorbed adsorbate compound.

Defective coffee beans amount to 15-20% of the total produced coffee beans. The defective coffee bean contains caffeine, which can negatively affect the human body, such as increased heart rate, and thus sensitive to consumption by some people. This study aims to optimize the decaffeination process of defective coffee beans. The extraction of aroma and flavor compounds was done by maceration, and the decaffeination was carried out using palm oil as a solvent. The type of beans (green and roasted beans), the decaffeination contact time, and the ratio between coffee bean extract and solvent were varied in this study. The caffeine content was quantified, and the organoleptic and color tests were done on the concentrated coffee extracts. It was found that the higher the amount of solvent volume in decaffeination, the higher the caffeine decrease. In addition, the longer the green beans’ decaffeination time, the lower the caffeine decrease. Decaffeination using green coffee beans resulted in a greater reduction of caffeine (6.515-48.241%) than roasted coffee beans (8.495-24.272%). The optimum operating condition of green coffee bean decaffeination was the coffee bean extract and solvent ratio of 1:5.82 and the decaffeination time of 26.5 minutes. The organoleptic test result shows that decaffeinated coffee flavor had the same preferability as the commercial coffee flavor and was thus able to compete in the market.

Drying is one of the key steps in the coffee production process. It is necessary to dry the coffee extracts to prevent microbial growth and to prolong the storage time of coffee. To this date, mechanical drying methods have been developed and employed in industries to shorten the drying time. However, these drying methods could alter the physicochemical properties of coffee and the compounds present in coffee. Therefore, it is crucial to maintain these factors in the coffee production process as they affect the stability, reconstitution, and aroma of the coffee produced. These properties are crucial as they determine the final quality of coffee. This review will focus on the effect of spray-drying, freeze-drying, and spray-freeze–drying on the physicochemical properties of coffee such as morphology, particle size, moisture content, bulk density, and compound retention. Effects on organoleptic properties are also discussed. Possible advancements to these drying methods such as the encapsulation process, the use of a porous frozen sample, and total solid enhancement of the raw material have been highlighted.

Abstract One of the important food additives used in the food industry is betalain, which is applied as a natural dye. Red beet is the most common resource of betalain. To increase its shelf life, encapsulation followed by drying is commonly carried out. However, betalain is a heat‐sensitive pigment that is susceptible to degradation on thermal exposure. Moreover, drying could affect the color, shape, structure, nutrition, and content of other ingredients in betalain. This review paper provides a discussion of (1) various drying methods such as spray drying, freeze drying, vacuum drying, and their effects on the quality of the dried betalain products; (2) stability and properties of betalain pigment obtained by encapsulation using different carrier agents such as maltodextrin, gum arabic, starch, inulin, and protein; (3) several drying pretreatment and posttreatment processes to improve the recovery and stability of betalain such as extraction and optimum storage conditions. Additionally, a summary and future perspectives for further research are also provided in each section of drying methods.