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Purple flesh sweet potato or Ipomea batatas is one of the most important crops in Malaysia. Currently the crop is exclusively consumed and marketed in a dried form as traditional snacks and chips. So, understanding the moisture sorption isotherms of this crop is imperative for determining its storability and optimal shelf life of the dried product. Thus, the objective of this study was to determine the adsorption isotherms of purple flesh sweet potato experimentally and the data obtained were used to model the process at different temperatures by employing several mathematical models using non-linear regression analysis. Several mathematical models (GAB, BET, Oswin, Chung and Pfost, Peleg, Henderson, Langmuir, Caurie and Halsey) were tested and compared with the experimental data. The best fitting mathematical model for all temperatures was Caurie’s equation with highest R2 value within the range of 0.9919 and 0.9949 and lowest chi square (λ2) values of 0.0000151–0.0000229. The monolayer moisture content for optimum moisture level for safe storage can be obtained from BET, GAB and Caurie equations. The monolayer moisture content from the GAB equation were found to be 0.1314, 0.1253 and 0.1182 kgw/kgDM and from Caurie’s equation, the values were 0.071, 0.0707 and 0.0692 kgw/kgDM. Both at 25 °C, 50 °C and 60 °C respectively.

Incomplete removal of chromium from discharge effluent of chromium-based industries is a serious problem due to its deleterious effect. ChromeBac™ is a locally developed Cr(VI) reduction system carried out by aerobic Cr(VI) resistant bacteria followed by chemical precipitation. The locally isolated Cr(VI) resistant-reducing Acinetobacter haemolyticus EF369508 was immobilized onto carrier materials inside a 50 L bioreactor. Mixture of 10% (v/v) liquid pineapple waste and neutralized Cr(VI) solutions (30–60 mgL−1) was fed into the bioreactor at 0.11 m3 h−1. Around 90% of the initial Cr(VI) was reduced after 24 h of contact inside the bioreactor. Residual Cr(VI) was then further reduced to between 1.0 and 1.5 mgL−1 by immobilized chromate reductase alginate-beads packed in a 10 L flow-through column, after 15 h of contact. Some important characteristics for the chromate reductase activities for A. haemolyticus are as follows; not NADH-dependent, associated with CFE with notable contribution from the membrane fraction, enhanced in the presence of glucose, optimal at pH 7.0, 30 °C, in the presence of 1 mM Co2+ (highest) with Michaelis–Menten constant, Km and maximum reaction rate, Vmax of 184.47 μM and 33.3 nmol/min/mg protein respectively. Ag+ and Hg2+ inhibited the enzyme activity. This study demonstrated the potential of using immobilized chromate reductase beads to further reduce residual Cr(VI) present in the effluent of a ChromeBac™ process, hence reducing the time for overall Cr(VI) treatment process.

The development of advanced and modern instrumentation techniques make the identification and quantification of food contaminants analysis easier. This chapter discusses several instrumentation techniques widely used for halal adulteration in food/beverages such as Fourier transform-infrared spectroscopy (FTIR), polymerase chain reaction (PCR), gas chromatography (GC), high performance liquid chromatography (HPLC), differential scanning calorimetry (DSC), proton transfer reactions-mass spectroscopy (PTR-MS), proton nuclear magnetic resonance (1H NMR) spectroscopy, and electronic nose. Major advances in the field of chemometrics combined with the use of some instrumentation such as FTIR, DSC provide better quantification process of food contaminants. The basic principles of each technique are also summarized to facilitate better understanding of identification and quantification of halal adulteration in food and beverages.

The potential of agricultural waste as substitute for rich-growth medium for bacteria during Cr(VI) reduction was investigated using the locally isolated Cr(VI) resistant-reducing strain of Acinetobacter haemolyticus and sugarcane bagasse. A. haemolyticus showed higher resistance to 100 mg/L Cr(VI) in Luria Bertani (>1010 CFU/mL) compared to sugarcane bagasse (106 CFU/mL). Higher Cr(VI) reduction by the SCB-immobilized bacteria (>90%) compared to in LB only (around 25%) clearly indicated the role of SCB in carrying out abiotic reduction of Cr(VI) as well as Cr(VI) adsorption. Nevertheless, Cr(III) was detected on the bacterial surface using Electron Spin Resonance (ESR) and electron microscopy (FESEM–EDX) analysis. The Cr(III) deposition occurred probably via complex formation with either carboxyl, hydroxyl or amide groups present on the bacterial cells surface as suggested from the FT-IR analysis. TEM analysis further showed Cr distribution at the membrane and cytosolic fractions. This work clearly demonstrated the role of bacteria in reducing Cr(VI) to Cr(III) as well as the potential of using agricultural waste material such as SCB to carry out abiotic Cr(VI) reduction.

Today’s food industry and retailers are trying to address the growing demand for convenience by considerable expansion of pre-prepared meal solutions, for example ready meals (also called meals ready-to-eat, MRE) (Geeroms et al. 2008; Olsen et al. 2010). Due to the socio-economic evolutions and the busy and hectic lifestyle, ready meals have become a popular meal solution for many people around the world. Based on the retail value of US$92.2 billion in 2012, Euromonitor International (2013) has pointed that ready meal secures a noteworthy market and it is expected to maintain this momentum in the forthcoming years up to 2016.

The bacterial reduction of Cr(VI) from industrial wastewater was evaluated using a 2.0-m(3) bioreactor. Liquid pineapple waste was used as a nutrient for the biofilm community formed inside the bioreactor. The use of rubber wood sawdust as packing material was able to immobilize more than 10(6) CFU mL(-1) of Acinetobacter haemolyticus cells after 3 days of contact time. Complete reduction of 15-240 mg L(-1) of Cr(VI) was achieved even after 3 months of bioreactor operation. Cr(VI) was not detected in the final effluent fraction indicating complete removal of Cr from solution from the flocculation/coagulation step and the unlikely re-oxidation of Cr(III) into Cr(VI). Impatiens balsamina L. and Gomphrena globosa L. showed better growth in the presence of soil-sludge mixture compared to Coleus scutellarioides (L.) Benth. Significant amounts of Cr accumulated at different sections of the plants indicate its potential application in Cr phytoremediation effort. The bacterial-based system was also determined not to be detrimental to human health based on the low levels of Cr detected in the hair and nail samples of the plant operators. Thus, it can be said that bacterial-based Cr(VI) treatment system is a feasible alternative to the conventional system especially for lower Cr(VI) concentrations, where sludge generated can be used as growth supplement for ornamental plant as well as not detrimental to the health of the workers.