Celery (Avium graveolens L.) has been naturally used to treat hypertension and cancer. Fresh celery contains a high water content of approximately ±86% which may lower the quality upon storage for a long time. Drying was applied to reduce moisture content in order to prolong the shelf-life. Drying of celery was carried out using a self-designed photovoltaic-thermal (PV/T) solar dryer as well as conventional dryers such as oven and vacuum oven for the comparisons at an approximate temperature of 49°C. The PV/T solar dryer was able to simultaneously convert the solar energy into thermal and electrical energy. The electrical energy was in turn used to drive the blowers to create a forced convective flow of heat transfer. Drying in the PV/T solar dryer was carried out in 3 different weather conditions while 3 different pressures (10; 40; 70 kPa) were tested during drying in the vacuum oven. The PV/T solar dryers demonstrated the best results in terms of constant drying rate (0.986 kg H2O/min.m2) and drying time (87 minutes). Total chlorophyll content retained was 5.42 mg/L. The PV/T solar dryer seemed promising to be further developed for an efficient drying process since it required low energy consumption while using the costless renewable solar energy.

Bubble pearls are a beverage product that is easy to consume and rich in antioxidants and is one of the innovations that can be used to process guava so that it does not rot easily. Bubble pearls are generally made from tapioca flour, sugar and water. This study aims to determine the most preferred bubble pearls formulation based on the sensory attributes of the additives in various forms of guava ingredients. Bubble pearls are made with four types of guava ingredients in the form of puree, flour, extract and paste. Making bubble pearls is added with tapioca flour, sugar and water. The ingredients for guava and tapioca flour use a ratio of 4: 1, 3: 2, 2: 3. The first stage sensory test is based on hedonic ranking of the elasticity, mouthfeel and overall attributes, the results of which are analyzed using two way anova. The second stage of sensory test is a hedonic rating of the attributes of taste, aroma, color, texture and overall, the results of which are analyzed using one way ANOVA. The second stage uses 30 panelists each who are not trained who are identified to like bubble pearls. The results of the first stage sensory test showed that the attributes of chewiness, mouthfeel and overall were guava flour, puree, pasta with a ratio of 4: 1 while the extract form was a 3: 2 ratio. The results of the second stage sensory test showed that the attributes of aroma, taste, texture, color, and overall were guava flour with a ratio of 4: 1. Overall,  the most preferred formulation for making  bubble pears is made from guava powder and tapioca flour with a ratio of 4:1.

Tomato is a fruit that does not last long (perishable), so it is necessary to find another alternative to increase its economic value. One of those alternatives that can be done is by making a fermented product called nata de tomato. Nata de tomato contains microbial cellulose which is formed by the bacteria Acetobacter xylinum. This microbial cellulose has some advantages over the typical cellulose found in common plants. Thus, it potentially could be further developed in the papermaking. This research was conducted to study the effects of combining microbial cellulose pulp from nata de tomato with tomato powder on paper quality, such as water content, grammage and water absorbency. In this research, the tomato filtrate was used as a growth medium for Acetobacter xylinum to produce nata de tomato. Then, nata de tomato was shredded into pulp, while its waste was dried into tomato powder and used as additional material for the pulp. This research was designed using a single factor experiment with variation in the addition of tomato powder by 0, 1, 3 and 5 % (w/w). The effects of this variation observed using variance analysis and significant test using the LSD (Least Significant Difference) method.