Field investigation on the operation of an industrial fluidized bed paddy dryer of 25 t/h capacity available in a processing complex of Padiberas Nasional Berhad (BERNAS) of Malaysia was carried out to assess its drying characteristics, energy consumption and quality of product during two paddy harvesting seasons. A grain drying simulation model was used to predict dryer performance which can be used as a basis for improving drying operations. For the first season (August-September), average drying rate was found to be 538 kg moisture/h to reduce moisture content (mc) from 36.98± 0.89% dry basis (db) to 27.58±0.79% (db) at 100-120°C of drying air temperature with a feed rate (capacity) of 7.75 t/h. In the second season (February-March), average drying rate was found to be 435 kg moisture/h to reduce mc from 28.14 ±0.68% (db) to 22.54 ± 0.69% (db) at 78-90°C drying air temperature with a feed rate of 9.5 t/h. The thermal and electrical energy consumptions were obtained as 7.57 and 0.97 MJ/kg water removed, respectively, for the first season, while 5.92 and 1.2 MJ/kg water removed for the second season. Higher head rice yield and whiteness and lower milling recovery were achieved during the first season than the second season at acceptable milling degree and transparency. Meanwhile, simulation results indicated that the dryer performed better in terms of increased drying capacity during the second than the first season; the dryer could be operated at 150°C to achieve almost double throughput capacity up to 20 t/h for the second season, while for the first season, high mc hindered the capacity to be at or below 7.75 t/h even when using higher a temperature of 160°C to reduce moisture to the desired final moisture of 24-25% (db). Proportion of slower vehicles based on users' opinion poll
Pink Guava Puree (PGP) factory produces tons of residues from its unit operation [refiner (R),
siever (S), and decanter (D)]. These residues represent a waste of nutrients and can contribute
to environmental problem. However, it can benefit related industries if the properties of the
residues are known. Thus, this research aims to determine the compositions of the residues
from PGP processing factory in order to evaluate possible value-added by-product and energy
sources. The residues from each unit operation were being tested for proximate composition,
dietary fibre components, pH value, emulsifying activity (EA) and emulsifying stability (ES),
carbon-to-nitrogen (C/N) ratio, and sugar analysis. The sugar content was analysed using High
Performance Liquid Chromatography (HPLC-RI detector). Results showed that the residues
have good composition of carbohydrate (11.82–12.18%), and thus potential as carbon source
and can be a good substrate for fermentation. These residues may also benefit the food industry
as a good source of dietary fibre (18.63–29.86%). The pH value for these PGP residues is 4;
thus they were considered as acidic food by-product. The low pH value also contributed to the
low EA and ES value other than the low content of protein in the sample. C/N ratio for PGP
residue from R (46:1) is the lowest compared to the C/N ratio from S (84:1) and D (115:1). The
amount of sugars detected in the PGP residues in descending order were fructose > glucose >
sucrose.