Effects of solar‐ and oven‐drying on physicochemical and antioxidant characteristics of hihatsumodoki ( Piper retrofractum Vahl) fruit

Abstract

The physicochemical and antioxidant properties of whole hihatsumodoki (Piper retrofractum Vahl) pepper fruits were evaluated before and after solar‐ and oven‐drying. Desirable dry matter (24% relative mass) and aw (0.50) values were obtained after solar‐drying for 18 hr, and oven‐drying for 24, 6, and 4 hr at 50, 70, and 90 °C, respectively. The color parameters (Hunter a* and b* values) of the fruits were affected by their drying conditions. Principal component analysis was used to determine suitable drying conditions to obtain dried pepper fruits with desirable food and color properties. The piperine contents of the dried pepper fruits were maintained under all of the drying conditions tested. However, solar‐drying for 18 hr and oven‐drying at 90 °C for 6 hr resulted in significant reductions in their total phenol contents and DPPH radical scavenging activities. The results of this study may be useful for optimizing the drying of whole hihatsumodoki fruits. Practical applications This work aimed to study the effects of solar‐ and oven‐drying processes on the physicochemical properties of an economically important species of pepper fruits, hihatsumodoki. A range of drying conditions was examined, and the optimal conditions were determined to maintain pungency and antioxidant activity while achieving a sufficiently low water activity to prevent microbial growth and spoilage. The present study serves as an important work in providing insights into how the thermal and UV stabilities of piperine and phenolic compounds in hihatsumodoki pepper fruits affect the physicochemical and antioxidant properties when the fruits are subjected to different drying conditions. The work described in this paper will be of use to a wide range of readers interested in optimizing drying processes based on experimental data, and may be applicable to a variety of Piperaceae.

Experimental Characterization of the Drying of Kampot Red Pepper (Piper nigrum L.)

“…Table 2 and Figure A4 in Appendix C present the ratio of the piperine content of dry grains to the piperine content of fresh grains, as a function of the boiling time, for the two drying temperatures: 55 • C and 65 • C. The results and their statistical analysis show that the drying, with or without pretreatment, does not seem to influence the piperine content of the grains (p-value = 0.32). These results are totally coherent with those that were obtained in several studies, when considering pepper with different origins [19][20][21]. This good conservation of the piperine is probably due to the fact that the piperine molecules are mostly located in the inner core of the grains, rather than in the skin [22].…”

Unjuk Kerja Pengering Tenaga Surya Tipe Efek Rumah Kaca Untuk Pengeringan Cabai Dengan Perlakuan Low Temperature Long Time Blanching

“…Sebaliknya, jika cuaca mendung atau banyak terdapat tutupan awan, maka intensitas penyinaran matahari akan rendah sehingga suhu yang diterima oleh ruang pengeringpun akan menjadi lebih rendah. Tinggi rendahnya intensitas penyinaran matahari ini sangat berpengaruh terhadap suhu di dalam ruang pengering, yang juga akan berpengaruh terhadap kecepatan penurunan kadar air pada bahan yang sedang dikeringkan (Martiani et al, 2017;Takahashi et al, 2017).…”

Perubahan Fisiko-Kimia Cabai Puyang (Piper Retrofractum Vahl.) Pada Pengeringan Hot Air Dryer

“…Pada suhu 70C, penurunan kadar air cabai puyang lebih cepat dibanding pada suhu 50 dan 60  C. Di sisi lain, waktu yang diperlukan untuk mencapai kadar air keseimbangan lebih cepat tercapai pada suhu pengeringan 70C. Peningkatan suhu akan mempercepat proses perpindahan massa air dari bahan ke ruang pengering (Takahashi et al, 2017). Hal ini juga sesuai dengan hasil penelitian…”

“…Kandungan antioksidan sampel blanching lebih rendah karena adanya pemberian panas sehingga menurunkan kandungan antioksidannya. Penurunan ini erat kaitannya karena keberadaan antioksidan pada bagian kulit luar cabai puyang sehingga sangat dipengaruhi dengan temperatur pemanasan dalam mesin pengering (Nakatani et al, 1986;Takahashi et al, 2017).…”

“…Kandungan piperin sampel blanching sedikit lebih rendah dari sampel non-treatment. Hal ini sesuai dengan penelitian Takahashi et al, (2017) yang menyatakan bahwa kandungan piperin pada cabai puyang kering relatif konstan mulai awal pengeringan hingga akhir pengeringan baik pada metode pengeringan di bawah matahari terbuka maupun pengeringan dalam oven. Hal ini dikarenakan bahwa piperin lebih banyak terdistribusi di dalam buah bukan di permukaan buah, sehingga terjaga dari pengaruh iradiasi UV dan juga temperatur mesin pengering (Nair, 2004;Nisha et al, 2009).…”