NSC 952221E451001 1

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NSC 952221E451001 1

Effects of physico-chemical properties of buckwheat and adlay on post-expansion and glass transition of extruded pellets (pellets) (expansion ratio, ER) - - (Modified Rapid Visco Analysis) L 41.7±5.7 48.1±2.3 77.4±2.6 300ºC 3040 2.5±0.7 3.6±0.6 40 a/b 60 3035 (pasting temperature)(75.5±0.2ºc) ( 70.8±0.6ºC and 69.0±0.3ºC) (R=0.39) (normalized holding strength, nhs, holding strength 1st cycle / final viscosity) (R 2 ) 0.78 (nhs, [holding strength 1st cycle - holding strength 2nd cycle ] / final viscosity) nhs R 2 =0.92 (peak time) 0.94 2

Abstract The purpose of this research was to investigate the influence of rheological properties of buckwheat and adlay on expansion properties of their products. Therefore, a prediction model of expansion of pellets were also established and become the core platform for developing functional snack foods. The results showed both adlay and buckwheat pellets had profound enzymatic browning reaction. L values of adlay and buckwheat pellets were 41.7±5.7 and 48.1±2.3, while the value of pellets made with waxy rice was 77.4±2.6. However, pellets made with adlay and buckwheat were darker than waxy rice. Increasing toasting temperature (T temp.) resulted in the decreasement of bulk density. The higher the T temp., the bigger the ER of products was. The ERs of adlay and buckwheat pellets toasted at 300ºC were smaller than waxy rice, and it took 30~40sec for the pellets to reach the plateau or maximum ER before degraded by heat. The addition of 50% waxy rice flour to adlay or buckwheat pellets could raise their ERs from 2.5±0.7 to 3.6±0.6, and reduce the hardness of products significantly, but improve their crispness. The a/b values increased and Maillard reaction occurred obviously while toasting time (T time) was longer than 40sec. At T time over 60sec, heat degradation of pellets started and their colors became darkening. Therefore, the T time of 30~35sec was regarded as suitable to get a better ER and lesser degradation of functional ingredients. In this report, Modified Rapid Visco Analysis was used to measure the viscosities of samples by two continuous heat-hold-cool temp. cycles. It also showed the pasting temp. (PT) of adlay flour (75.5±0.2ºC) was higher then buckwheat and waxy rice (70.8±0.6ºC and 69.0±0.3ºC, respectively), but there was no good linear relationship between PT and ER (R 2 =0.39). However, ER increased with normalized holding strength (nhs), which was defined as holding strength in the first cycle (HS 1 ) divided by final viscosity (FV), more significantly than HS 1 or FV. The R 2 between ER and nhs was about 0.78. The correlation between ER and nhs, which was defined as HS 1 minus HS 2 and then divided by FV, was more significant (R 2 =0.92) than correlation between ER and nhs. But it was found that the R 2 between peak time and ER was about 0.94, which was the best one. This research provided valuable information for prediction of ERs and future development of functional snack foods. Keywords: adlay, buckwheat, expansion ratio, Rapid Visco Analysis, functional snack foods. 3

(common buckwheatfagopyrium esculentum Moench) (tatary buckwheat Fagopyrium. tataricum Gaertn) ( ) ( ) (Pomeranz,1983) 香 苷 (rutin) (quercetin) (flavanoids) (Pomeranz Robbinas, 1972) (Sun Ho, 2005.) (Oomah Mazza, 1996) (Tomotake, 2000.) (Prestamo, 2003) (Kawa, 2003.) (Kim, 2003.) (Li Zhang, 2001.) ( ) Mariotti (2005) 11.0 (5.36.3) (8.9) (, 2001) (buckwheat) (Polygonaceae) (Fagopyrium) 4

(adlay job s tear) (pellets) (Gramineae) (Coix lachryma-jobi L. var. ma-yuen Stapf) (1716-1731) 69 (, 1994) (coixenolide) (Ukita Tanimura, 1961.) Otsuk (1988) (, 1996, 2000.) (, pellet ( ) 1998) Chung (Harper, (1988) 1981) Chen and Yeh, 2001 ( ) pellet pellet pellet (, 1994) glass transition temperaturet g (2004) state diagram 2001 5

) (94 I ) 2. (1) Lightness (L)a b (2) (Bulk density) (3) (Rapid (pellets) Visco Analyzer, RVA TM, Australia) - - (4) (pellets) 23 1. 150225 300±5ºC (, Taichung I) (5) (, Taichung I) (, Taichung Waxy 70) (95 10 4560 3060 (, pellets) 77.4±2.6 L 41.7±5.7 48.1±2.3 6

(PT) ( 1 ABW (75.5±0.2ºC) (PV) ) 150225 300ºC 519±33cPs (69.0±0.3ºC) PV (3107±36cPs) PT 70.8±0.6ºC (PT) ( 2) (ER) (R 2 =0.39)( 300ºC 5) (holding strength 1st cycle, HS 1 ) 300ºC (final viscosity, FV) 3040 (normalized holding ( 2A) strength, nhs) 1 / final viscosity nhs 2.5±0.7 3.6±0.6( 2A 2B) (R 2 ) 0.78( 6) HS 1 HS 2 FV 40 a/b (nhs) 7 nhs (3) 4 nhs 50 (AW) (0.92) (Peak Time) 0.94 (8) 0 30 60 0.2389(PTime) 2 3.3554(PTime)+14.271 60 R 2 0.94 nhs 3035 3. RVA 46.359(nHS) 2 0.3751(nHS) +2.4236 R 2 0.92 RVA TM (RVA TM general pasting model) - (Peak Time) nhs 7

DMA 1. ( 1) ( 1 2 2A2B 3 4 ) 3. ( 3) 4. (R 2 ) 0.92~0.94( 5678) RVA 2001 2001 1994 21(1)67-74 1998 25638-650 1996 Chen, C. M., and Yeh, A. I. 2001. Effect of amylose content on expansion of extruded rice pellet. Cereal Chem. 78:261-266. Chung, B. S., Suzuki, H., Hayakawa, S., Kim, J. H. and Nishizawa, Y. 1988. Studies on the plasma cholesterol-lowering component in Coix. Nippon Shokuhin Kogyo Gakkaishi. 35(9): 618-623. Harper, J. M. 1981. Extrusion of foods. Vol. I&II. CRC Press, Florida. Kawa, J. M., Taylor, C. G. and Przybylski, R 2003. Buckwheat concentrate reduces serum glucose in Streptozotocin-diabetic rats. J. Agr. Food Chem. 51(25): 7287 7291. Kim, C. D., Lee, W.-K., No, K.-O., Park, S.-K., Lee, M.-H., Lim, S. R. and Roh, S.-S. 2003. Anti-allergic action of buckwheat (Fagopyrum esculentum Moench) grain extract. International Immunopharmacology 3: 129-136. Li, S. and Zhang, Q. H. 2001. Advances in the development of functional foods from buckwheat. Critical reviews in Food Science and Nutrition 41(6): 451-464. Mariotti, M. Alamprese, C., Pagani, M. A. and Lucisano, M. 2005. Effect of puffing on ultrastructure and physical characteristics of cereal grains and flours. J. Cereal Sci. 43: 47-56.(Accepted 28 June 2005) Oomah, B. D. and Mazza, G. 1996. Flavonoids and antioxidative activities in buckwheat. J. of Agri. Food Chem. 44: 1746-1750. Otsuka, H., Hirai, Y., Nagao, T. and Yamaski, K. 1988. Anti-inflammatory activity of benzoxazinoids from roots of Coix lachryma-jobi L. var. ma-yuen. J.Natu. Prod. 51:74-79. Pomeranz,Y. 1983. Buckwheat: structure, composition, and utilization. CRC Critical Review in Food Science and Nutrition. 19:213-259. Pomeranz, Y. and Robbinas, G. S. 1972. Amino-acid composition of buckwheat. J. Agric. Food Chem. 20:270-274. Prestamo, G., Pedrazuela, A., Penas, E., Lasuncion, M. A. and Arroyo, G. 2003. Role of buckwheat diet on rats as prebiotic and healthy food. Nutrition Research 23: 803-814. Sun, T. and Ho, C.-T. 2005. Antioxidant activities of buckwheat extracts. Food Chem. 90: 743-749. Tomotake, H., Shimaoka, I., Kayashita, J. and Yokoyama, F. 2000. A buckwheat protein product suppresses gallstone formation and plasma cholesterol more strongly than soy protein isolate in hamsters. The Journal of Nutrition 130(7): 1670-1674. Ukita, T. and Tanimura, A. 1961. Studies on anti-tumor components in the seeds of Coix Lachryma- jobi L. var. ma-yuen (Roman.) Stapf. I. Isolation and anti-tumor activity of coixenolide. Chem. Pharm. Bull. 9: 43-46. 8

1 ( ) 2 Table 1 Composition of pellets and their colors. Table 2 Effects of toasting temp. on BD&ER of ABW. Composition (%) Parameters of Color Toasting Temperature Adl Bkw Wxr L a b Toasting 150 o C 225 o C 300 o C Time A 100 -- -- 41.7±5.7 8.5±0.8 12.7±2.7 (sec) BD: Bulk Density (g/cm 3 ) B -- 100 -- 48.1±2.3 8.2±0.1 13.9±0.1 [ER]: Expansion Ratio W -- -- 100 77.4±2.6-0.3±0.6 13.0±0.8 1.26±0.07 0.65±0.32 0.41±0.04 30 AW 50 -- 50 43.6±0.9 10.0±1.1 17.1±1.0 [ 1.0±0.1 ] [ 2.3±0.9] [ 3.2±0.3 ] BW -- 50 50 50.6±2.6 7.7±0.7 14.3±1.1 0.77±0.25 0.50±0.04 0.41±0.04 60 AB 50 50 -- 39.0±1.8 7.9±2.5 12.8±1.8 [ 1.8±0.7 ] [ 2.6±0.2 ] [ 3.2±0.3 ] ABW 33 33 33 43.2±1.2 10.0±0.9 16.9±1.1 0.58±0.02 0.50±0.03 0.35±0.03 120 Adl: Adlay, Bkw: Buckwheat, Wxr: Waxy rice [ 2.2±0.1 ] [ 2.6±0.1 ] [ 3.7±0.3 ] Expansion Ratio 7.0 6.0 5.0 4.0 3.0 Pellet A Pellet B Pellet W Expansion Ratio 7.0 6.0 5.0 4.0 3.0 Pellet AW Pellet BW Pellet AB Pellet ABW 2.0 2.0 1.0 0 20 40 60 80 100 120 Toasting Time (sec) 1.0 0 20 40 60 80 100 120 Toasting Time (sec) 2A (A) (B) (W) 2B (Wxr) (Adl) (Bkw) Figure 2A. Differences of ERs between pellet A, B&W. Figure 2B. Effects of Wxr addition on ER of Adl & Bkw. 1.3 a / b 1.1 0.9 0.7 0.5 0.3 0.1-0.1 0 20 40 60 80 100 120 Toasting Time (sec) 3 a/b Figure 3. Relationships between a/b and toasting time. 4 (AW) Figure 4. Pellet AW at various toasting time. 9

3 RVA Table 3. Expansion ratio, peak time, pasting temperature and viscosities of various flours analyzed by modified RVA. Flour PV P Time PT HS 1 HS 2 Breakdown MV FV Setback1 Setback2 ER A B W AW BW AB WAB PV: Peak Viscosity HS 1 : Holding Strength in the 1st cycle. MV: Midle Viscosity Setback1: MV - HS 1 = Setback1 P Time: Peak Time HS 2 : Holding Strength in the 2nd cycle. FV: Final Viscosity Setback2: MV - PV = Setback2 PT: Pasting Time Breakdown: PV - HS 1 = Breakdown ER: Expansion Ratio of products 5 6 (nhs) Figure 5. The relationship between PT and ER. Figure 6. The relationship between nhs and ER. nhs) 8 Figure 7. The relationship between nhs and ER. Figure 8. The relationship between P Time and ER. 10