Satoru Nakashima is Professor of Physical Geochemistry at Osaka University and has been developing non-destructive evaluation methods of earth, planetary and environmental materials and quantifying their changes with time. In particular, he pioneered spectro-colorimetry of rocks and soils and has been applying it to degradation of rocks. He has recently developed handy spectro-colorimeters in the visible to near infrared wavelength range and now is using them for measuring ripening, aging and degradation processes of plants (vegetables and fruits) and meats. He is aiming at founding a Non-Profit Organization on Earth’s Environmental Health including safety of plants and foods, after his retirement form Osaka University in 2 years. He wishes to collaborate with experts from all over the world to maintain the health of our natural environment.
Ripening, aging and degradation processes of foods are essential for evaluating conditions and safety of foods. The timing of harvesting vegetables/fruits is often empirical depending on farmers’ experiences. After the harvest, some show further ripening before aging and degradation. Despite some data on high temperature (> 50oC) behavior of foods during drying and cooking conditions, changes with time of foods at environmental temperatures around 25oC have not been studied quantitatively. In this study, a handy visible – near infrared spectrometer (PRISMO MIRAGE) have been developed and applied to monitor color and spectral changes with time of some vegetables and fruits either under natural outdoor conditions (Ripening : 5-35oC) or in containers (Aging/Degradation: 15-35oC). Changes with time in a* color values (reddishness) and in peak heights at 675 nm in visible spectra are analyzed for determining the first order decrease rates of a* and chlorophylls, respectively. These rate constants are plotted in Figure 1 together with some literature data on food drying processes. Decrease rates of a* color value during the final degradation of tomato at around 20oC appears to be on the linear trend from those for drying of green peas at 70-100oC (Figure 1). The decrease rates of lycopene/carotenoid for tomato pure during drying are also on the similar trend. Increase rates of a* value during ripening (green to red) of bell pepper at 30oC are also close to these trends. Decrease rates of chlorophylls by 675 nm peak heights for the same ripening processes of bell pepper is slower than the a* increase rates but close to the extrapolation of chlorophyll decrease rates during bell pepper drying at 40-70oC. The chlorophyll decrease rates are considered to control some of the ripening and degradation processes of vegetables and fruits.
Ms. Tee Yei Kheng is a research officer in Malaysian Cocoa Board since 2013 and currently, she is also a PhD candidate in Universiti Putra Malaysia (UPM). She has the research interests in plant physiology and precision agriculture. Ms. Tee is also the Head of Project for a research funding under 11th Malaysian Plan (2016-2020) with 10 research projects have been carried out to study the effects of climate changes on cocoa productivity. Despite that, she has the interests in applying Geographical Information System (GIS) and spectral reflectance of cocoa in response to nutrient deficiency and plant stress through precision cocoa management which grant her another research funding under 11th Malaysian Plan for 5 years (2016-2020). She was the first Borlaug Fellow from Malaysia in 2015 to join The Norman E. Borlaug International Agricultural Science and Technology Fellowship Program. This program was supported by WCF and the U.S. Department of Agriculture Foreign Agricultural Service.
The detection of pigments in cacao pods together with colourless flavonoids serves as a useful indicator for pod maturity using a fast and non-destructive multiparametric fluorescence sensor. In this study, the contents of anthocyanin, flavonol, chlorophyll and nitrogen balance of five cacao genotypes (DESA1, KKM22, KKM25, MCBC1 and PBC221) were determined monthly (1-5 months) after flower pollination. There were significant differences (P≤0.05) observed between the interaction of five different cacao clones and pod development periods in flavonol, chlorophyll and nitrogen balance contents. As pods developed, anthocyanin and flavonol accumulated while the content of chlorophyll decreased only when pod matured with nitrogen balance showed a decreasing trend in cacao pods. Among these clones, as expected, natural red appearance in cacao pods of DESA1 showed significantly highest index of anthocyanin (0.637), following by KKM22 (0.255). In addition, there was no significant difference observed in KKM25, MCBC1 and PBC221 for anthocyanin content. During pod development, MCBC1 showed the least content in flavonol (P≤0.05) and the chlorophyll contents in KKM22 and MCBC1 were lower compared to other clones. UPLC-QTOF analysis showed that major components found at the cacao peel extracts of the pods consisted of flavonoid and procyanidin which are commonly found in cacao beans. Besides phenolic compounds, the presence of methyl xanthine (theobromine and caffeine) was found in cacao peel. As a conclusion, non-destructive fluorescence-based indices can be used to measure the pigments and flavonoids in cacao which can provide valuable non-destructive indicators for cacao pod maturity across different cacao cultivars.