SIXTH INTERNATIONAL CONFERENCE SUSTAINABLE FOOD AND POSTHARVEST TECHNOLOGIES

SIXTH INTERNATIONAL CONFERENCE SUSTAINABLE FOOD AND POSTHARVEST TECHNOLOGIES - INOPTEP 2019 KLADOVO, SERBIA, April 07 th – 12 th, 2019 SELECTED PROPERTIES OF HVED TREATED COCOA SHELL Veronika Barišić, Ivana Flanjak, Antun Jozinović*, Drago Šubarić, Jurislav Babić, Borislav Miličević, Đurđica Ačkar Josip Juraj Strossmayer University of Osijek, Faculty of Food Technology Osijek, Franje Kuhača 20, 31 000 Osijek, Croatia Introduction In the chocolate industry, the main by-product is a cocoa shell that is separated from cocoa bean before or after the roasting process. As the cocoa shell is becoming increasingly difficult to dispose of, there is a need to explore the new solutions for its application. This study aimed to determine the effect of HVED (high voltage electrical discharge) treatment on selected cocoa shell properties. HVED is a non-thermal treatment which is performed in water and usually is used for extraction and decontamination of different foods and by-products. Materials and methods From fermented and roasted (135 °C for 55 minutes) cocoa beans cocoa shell was separated and treated with high voltage electrical discharge directly in water. Samples were treated at 40 and 80 Hz for 15, 30 and 45 minutes in two different concentrations (1% and 3%). Control samples were treated in the same way only in water. Total fat content was determined by Folch method, and fatty acids were measured by gas chromatography. Water activity is determined by Hygro. Lab 3, Rotronic. The effect of HVED on the colour of the samples was determined with Chroma Meter CR-400, Konica Minolta. Results and discussion Table 1. Total fat and fatty acid content of untreated and treated cocoa shell samples Sample Total fats (%) C 14: 0 (%) C 16: 1 (%) C 17: 0 (%) C 18: 1 (%) C 20: 0 (%) C 18: 3 (%) C 22: 0 (%) C 20: 3 (%) C 24: 0 (%) Untreated cocoa shell 3. 58 ± 0. 52 0. 87 ± 0. 08 24. 36 ± 0. 82 1. 12 ± 0. 06 0. 22 ± 0. 00 23. 99 ± 1. 21 30. 24 ± 0. 44 0. 90 ± 0. 16 1. 14 ± 0. 07 0. 14 ± 0. 01 0. 78 ± 0. 09 0. 06 ± 0. 01 1. 5%, 15 min 2. 75 ± 0. 01 1. 17 ± 0. 03 24. 13 ± 0. 17 1. 53 ± 0. 02 0. 21 ± 0. 00 20. 32 ± 0. 61 30. 29 ± 0. 36 1. 11 ± 0. 02 1. 15 ± 0. 03 0. 14 ± 0. 01 0. 82 ± 0. 02 0. 07 ± 0. 01 1. 5%, 30 min 2. 63 ± 0. 16 1. 21 ± 0. 08 24. 61 ± 0. 16 1. 55 ± 0. 04 0. 25 ± 0. 02 20. 79 ± 0. 70 30. 34 ± 0. 23 1. 12 ± 0. 01 1. 18 ± 0. 05 0. 15 ± 0. 00 0. 81 ± 0. 06 ± 0. 01 1. 5%, 45 min 2. 73 ± 0. 02 1. 16 ± 0. 01 24. 61 ± 0. 02 1. 60 ± 0. 02 0. 20 ± 0. 00 19. 06 ± 0. 36 29. 76 ± 0. 58 1. 01 ± 0. 05 1. 03 ± 0. 05 0. 12 ± 0. 00 0. 63 ± 0. 06 0 1. 5%, 15 min, 40 Hz 2. 86 ± 0. 13 0. 94 ± 0. 04 24. 22 ± 0. 04 1. 34 ± 0. 02 0. 20 ± 0. 01 21. 36 ± 0. 07 31. 46 ± 0. 12 1. 07 ± 0. 01 1. 24 ± 0. 01 0. 13 ± 0. 01 0. 83 ± 0. 00 0. 05 ± 0. 01 1. 5%, 30 min, 40 Hz 2. 61 ± 0. 06 1. 35 ± 0. 03 24. 71 ± 0. 03 1. 88 ± 0. 01 0. 24 ± 0. 03 18. 66 ± 0. 33 29. 46 ± 0. 15 1. 28 ± 0. 02 1. 14 ± 0. 04 0. 17 ± 0. 01 0. 80 ± 0. 10 0. 07 ± 0. 00 1. 5%, 45 min, 40 Hz 2. 57 ± 0. 07 1. 25 ± 0. 12 24. 02 ± 0. 63 1. 58 ± 0. 15 0. 21 ± 0. 02 18. 17 ± 0. 36 29. 25 ± 1. 13 1. 10 ± 0. 02 1. 10 ± 0. 01 0. 17 ± 0. 04 0. 87 ± 0. 03 0. 09 ± 0. 01 1. 5%, 15 min, 80 Hz 2. 46 ± 0. 03 1. 21 ± 0. 05 24. 04 ± 0. 79 1. 67 ± 0. 09 0. 25 ± 0. 01 20. 03 ± 0. 38 28. 78 ± 1. 20 1. 11 ± 0. 03 1. 12 ± 0. 02 0. 16 ± 0. 02 0. 85 ± 0. 00 0. 07 ± 0. 01 1. 5%, 30 min, 80 Hz 2. 69 ± 0. 04 1. 18 ± 0. 03 24. 70 ± 0. 14 1. 76 ± 0. 02 0. 26 ± 0. 01 20. 19 ± 0. 16 30. 26 ± 0. 09 1. 16 ± 0. 03 1. 15 ± 0. 02 0. 12 ± 0. 01 0. 86 ± 0. 01 0. 07 ± 0. 01 1. 5%, 45 min, 80 Hz 2. 61 ± 0. 04 1. 30 ± 0. 12 24. 18 ± 0. 82 2. 06 ± 0. 19 ± 0. 01 18. 60 ± 0. 60 28. 24 ± 1. 27 1. 22 ± 0. 06 1. 06 ± 0. 04 0. 17 ± 0. 01 0. 80 ± 0. 00 0. 07 ± 0. 02 3%, 15 min 3. 09 ± 0. 17 0. 99 ± 0. 08 24. 21 ± 0. 02 1. 19 ± 0. 02 0. 20 ± 0. 00 24. 16 ± 0. 23 29. 97 ± 0. 26 1. 00 ± 0. 02 1. 26 ± 0. 02 0. 21 ± 0. 00 0. 79 ± 0. 03 ± 0. 00 3%, 30 min 3. 32 ± 0. 21 0. 82 ± 0. 00 24. 52 ± 0. 02 1. 06 ± 0. 01 0. 21 ± 0. 00 25. 69 ± 0. 13 30. 01 ± 0. 04 0. 89 ± 0. 00 1. 27 ± 0. 01 0. 15 ± 0. 00 0. 74 ± 0. 00 0. 04 ± 0. 00 3%, 45 min 3. 06 ± 0. 03 0. 84 ± 0. 05 24. 35 ± 0. 07 1. 06 ± 0. 03 0. 20 ± 0. 00 25. 10 ± 0. 15 30. 14 ± 0. 06 0. 93 ± 0. 01 1. 38 ± 0. 00 0. 16 ± 0. 01 0. 82 ± 0. 03 0. 06 ± 0. 02 3%, 15 min, 40 Hz 2. 87 ± 0. 11 0. 90 ± 0. 01 24. 58 ± 0. 04 1. 04 ± 0. 01 0. 22 ± 0. 00 24. 51 ± 0. 27 30. 53 ± 0. 01 0. 88 ± 0. 01 1. 22 ± 0. 02 0. 16 ± 0. 01 0. 72 ± 0. 02 3%, 30 min, 40 Hz 2. 95 ± 0. 03 1. 05 ± 0. 02 24. 87 ± 0. 01 1. 14 ± 0. 01 0. 22 ± 0. 00 23. 71 ± 0. 12 30. 26 ± 0. 10 0. 93 ± 0. 01 1. 23 ± 0. 00 0. 21 ± 0. 00 0. 77 ± 0. 01 0. 06 ± 0. 01 3%, 45 min, 40 Hz 2. 86 ± 0. 04 1. 18 ± 0. 09 24. 20 ± 0. 14 1. 18 ± 0. 05 0. 20 ± 0. 01 21. 70 ± 1. 52 29. 92 ± 0. 43 1. 00 ± 0. 01 1. 19 ± 0. 12 0. 24 ± 0. 00 0. 78 ± 0. 06 0. 08 ± 0. 03 3%, 15 min, 80 Hz 3. 14 ± 0. 13 0. 97 ± 0. 06 24. 68 ± 0. 17 1. 07 ± 0. 06 0. 21 ± 0. 01 23. 91 ± 0. 72 29. 98 ± 0. 39 0. 91 ± 0. 09 1. 16 ± 0. 05 0. 18 ± 0. 01 0. 77 ± 0. 10 0. 06 ± 0. 01 3%, 30 min, 80 Hz 2. 62 ± 0. 15 0. 96 ± 0. 01 25. 18 ± 0. 15 1. 06 ± 0. 03 0. 21 ± 0. 00 23. 05 ± 0. 24 30. 76 ± 0. 07 0. 87 ± 0. 02 1. 17 ± 0. 00 0. 17 ± 0. 01 0. 69 ± 0. 01 0. 02 ± 0. 02 3%, 45 min, 80 Hz 2. 78 ± 0. 06 0. 85 ± 0. 05 24. 92 ± 0. 04 1. 07 ± 0. 05 0. 21 ± 0. 00 24. 79 ± 0. 28 30. 24 ± 0. 09 0. 93 ± 0. 03 1. 22 ± 0. 02 0. 17 ± 0. 00 0. 72 ± 0. 00 0. 08 ± 0. 03 Table 2. Colour values of cocoa shell samples Sample Untreated cocoa shell 1. 5%, 15 min 1. 5%, 30 min 1. 5%, 45 min 1. 5%, 15 min, 40 Hz 1. 5%, 30 min, 40 Hz 1. 5%, 45 min, 40 Hz 1. 5%, 15 min, 80 Hz 1. 5%, 30 min, 80 Hz 1. 5%, 45 min, 80 Hz 3%, 15 min 3%, 30 min 3%, 45 min 3%, 15 min, 40 Hz 3%, 30 min, 40 Hz 3%, 45 min, 40 Hz 3%, 15 min, 80 Hz 3%, 30 min, 80 Hz 3%, 45 min, 80 Hz L 47. 86 ± 3. 08 46. 51 ± 0. 02 45. 76 ± 0. 02 45. 27 ± 0. 01 46. 06 ± 0. 03 45. 71 ± 0. 02 45. 79 ± 0. 04 45. 26 ± 0. 03 46. 15 ± 0. 02 45. 47 ± 0. 02 43. 12 ± 0. 02 41. 73 ± 0. 06 41. 53 ± 0. 02 44. 13 ± 0. 03 44. 45 ± 0. 03 43. 73 ± 0. 03 44. 42 ± 0. 02 42. 40 ± 0. 02 42. 67 ± 0. 01 a 9. 23 ± 0. 44 8. 51 ± 0. 08 8. 59 ± 0. 12 8. 45 ± 0. 03 9. 00 ± 0. 06 8. 70 ± 0. 04 8. 77 ± 0. 04 8. 80 ± 0. 05 8. 74 ± 0. 04 8. 83 ± 0. 02 8. 89 ± 0. 02 8. 79 ± 0. 04 8. 91 ± 0. 04 8. 88 ± 0. 05 8. 85 ± 0. 03 8. 72 ± 0. 03 8. 91 ± 0. 05 8. 63 ± 0. 05 8. 59 ± 0. 07 b 17. 98 ± 0. 08 15. 48 ± 0. 07 15. 44 ± 0. 06 15. 02 ± 0. 04 16. 97 ± 0. 02 15. 45 ± 0. 03 15. 58 ± 0. 04 15. 65 ± 0. 03 15. 94 ± 0. 02 16. 16 ± 0. 03 16. 21 ± 0. 03 15. 60 ± 0. 05 15. 65 ± 0. 03 16. 14 ± 0. 03 16. 21 ± 0. 03 15. 85 ± 0. 05 16. 44 ± 0. 05 15. 15 ± 0. 03 14. 90 ± 0. 04 C 20. 21 ± 0. 13 17. 66 ± 0. 03 17. 67 ± 0. 02 17. 24 ± 0. 03 19. 22 ± 0. 01 17. 73 ± 0. 03 17. 88 ± 0. 02 17. 96 ± 0. 02 18. 18 ± 0. 01 18. 42 ± 0. 01 18. 49 ± 0. 03 17. 91 ± 0. 02 18. 01 ± 0. 04 18. 42 ± 0. 02 18. 47 ± 0. 02 18. 09 ± 0. 03 18. 70 ± 0. 03 17. 44 ± 0. 01 17. 20 ± 0. 01 h° 62. 84 ± 1. 20 61. 19 ± 0. 32 60. 77 ± 0. 25 60. 64 ± 0. 14 62. 07 ± 0. 20 60. 64 ± 0. 15 60. 62 ± 0. 15 60. 64 ± 0. 17 61. 27 ± 0. 13 61. 35 ± 0. 08 61. 25 ± 0. 04 60. 62 ± 0. 18 60. 35 ± 0. 10 61. 19 ± 0. 18 61. 36 ± 0. 10 61. 18 ± 0. 15 61. 53 ± 0. 18 60. 32 ± 0. 18 60. 04 ± 0. 28 ΔE 2. 93 ± 0. 05 3. 36 ± 0. 03 4. 01 ± 0. 03 2. 08 ± 0. 03 3. 36 ± 0. 03 3. 20 ± 0. 05 3. 51 ± 0. 03 2. 71 ± 0. 02 3. 03 ± 0. 02 5. 07 ± 0. 03 6. 59 ± 0. 07 6. 75 ± 0. 03 4. 17 ± 0. 04 3. 86 ± 0. 04 4. 67 ± 0. 04 3. 78 ± 0. 03 6. 18 ± 0. 03 6. 07 ± 0. 02 Total fats ranged between 2. 46 and 3. 58%, and all samples were found to have the highest content of oleic and stearic acid (Table 1). It was also concluded that HVED has no significant effect on fat content or fatty acid content. Any treatment had an influence on total colour change (∆E) of the samples. It is also noticed that all samples were in the domain of red (a) and yellow (b) colour. Decrease of L values indicates that treated cocoa shell was darker (Table 2). Also, it can be seen that water activity in all treated samples increased compared to the untreated cocoa shell (Figure 1). Acknowledgment This work has been supported by Croatian Science Foundation under the project „Application of cocoa husk in production of chocolate and chocolate-like products” (UIP 2017 -05 -8709) Figure 1. Water activity of untreated cocoa shell and treated samples *Corresponding author: ajozinovic@ptfos. hr