The present study investigated effects of microbial additives and silo density on chemical compositions, fermentation indices, and aerobic stability of whole crop rice (WCR) silage. The WCR (“Youngwoo”) was harvested at 49.7% dry matter (DM), and ensiled into 500 kg bale silo with two different compaction pressures at 430 kgf (kilogram-force)/cm2 (LOW) and 760 kgf/cm2 (HIGH) densities. All WCR forage were applied distilled water (CON) or mixed inoculants (Lactobacillus brevis 5M2 and Lactobacillus buchneri 6M1) with 1:1 ratio at 1x105 colony forming unit/g (INO). The concentrations of DM, crude protein, ether extract, crude ash, neutral detergent fiber, and acid detergent fiber of whole crop rice before ensiling were 49.7, 9.59, 2.85, 6.74, 39.7, and 21.9%, respectively. Microbial additives and silo density did not affect the chemical compositions of WCR silage (p>0.05). The INO silages had lower lactate (p<0.001), but higher propionate (p<0.001). The LOW silages had higher lactate (p=0.004). The INO silages had higher yeast count (p<0.001) and aerobic stability (p<0.001). However, microbial counts and aerobic stability were not affected by silo density. Therefore, this study concluded that fermentation quality of WCR silage improved by microbial additives, but no effects by silo density.
본 연구는 다양한 상대습도(11~93%) 조건에서 해조류의 미생물 안정성 및 품질특성에 미치는 영향을 조사하였다. 미생물 안정성은 저장 중 대장균군, 일반세균, 효모 및 곰팡이수를 분석하였다. 일반세균은 상대습도 69~93%에서 4.40~7.00 log CFU/g, 효모 및 곰팡이는 4.20~6.40 log CFU/g로 상대습도 69%이상 조건에서 일반세균, 효모 및 곰팡이의 수가 급격하게 증가하였다. 고결현상은 상대습도 11~53% 조건에서는 일어나지 않았으나 69, 81, 93% 조건에서는 각각 86.9, 99.45, 99.98%로 높은 고결현상을 가지는 것으로 나타났다. 색도는 상대습도가 높아질수록 L값과 b값이 감소하였고, a값이 증가하여 갈변현상이 일어났다. 또한, 총 페놀함량(9.10~8.66 mg GAE/100 g dw), ABTS 소거능(24.20~24.18 mg AAE/100 g dw), FRAP(15.34~15.33 mg Fe(II)/100 g dw)활성은 저장 중 상대습도 11~33%에서 가장 높게 유지되었다. 그러나, 상대습도 43~93%에서 저장 중 총 페놀함량(8.66~4.00 mg GAE/100 g dw), ABTS(22.57~4.50 mg AAE/100 g dw), FRAP(13.06~4.00 mg AAE/100 g dw)활성이 감소하는 것으로 나타났다. 상대습도 81% 조건에서 ABTS 및 FRAP이 1/3배로 감소하였고, 93% 조건에서 총 페놀함량, ABTS 및 FRAP이 각각 1/2배, 1/5배, 1/3배로 감소하였다. 따라서, 일반세균, 효모 및 곰팡이의 성장 억제, 고결현상 방지, 갈변억제, 높은 총 페놀함량과 항산화활성 유지를 위해서는 상대습도 53% 이하의 조건에서 보관하는 것이 미생물 안정성 및 품질특성 유지에 효과적일 것으로 판단된다.
본 연구는 생분해성 용기 개발의 연구성이 대두됨에 따 라서 동물성 재료로 제조한 생분해성 용기의 개발의 목적에 있다. 연구 결과 돈피, 우피, 닭피에 있어서 돈피가 우수한 수율과 단백질 분자량을 가진 것으로 나타났다. 이에 돈피를 이용하여 생분해 용기를 개발하였으며, 단면적 확인 결과 호두 껍질 분말 10%를 첨가한 처리구에서 적은 공극을 보였으며, 호두 껍질 분말 20%를 첨가한 처리구에서 공극의 크기가 큰 것을 확인할 수 있었다. 물성 연구 결과 호두 껍질 분말 10% 처리구가 더 높은 경도를 나타 내었으며, 호두 껍질 분말 20% 처리구가 더 높은 탄력성을 나타내었다. 압축강도는 호두 껍질 분말 20% 처리구가 더 높은 값을 나타내었다. General bacteria, E. coli 연구 결과 모든 일자에서 불검출되어 미생물로부터의 안정성은 더 장기간으로 실험해볼 필요가 있을 것으로 보인다. 또한 높은 항균 능력과 생분해능의 결과를 보여 저장 기간의 안정성이 높은 용기의 개발과 환경의 영향을 최소화 할 수 있을 것으로 판단된다. 따라서 돈피 젤라틴에 난각과 호두 껍질 분말을 넣어 제조한 생분해성 용기의 개발의 기초 데이터로 이용될 수 있을 것으로 생각된다.
The goal of this study was to evaluate effects of various microbial and organic additives on chemical compositions, fermentation indices, and aerobic stability of barley silage. Youngyang barley harvested at 31.5% dry matter (DM), and ensiled into 20 L bucket silo for 0, 1, 3, 7, 48, and 100 d in quadruplicates with four additives following: sterile destilled water at 1% of fresh forage (CON); Lactobacillus plantarum at 1.2 x 105 cfu/g of fresh forage (CL); Lactobacillus buchneri at rate of 1.2 x 105 cfu/g fresh forage (LB); Fermented Persimmon Extract at 1% of fresh forage (FPE); and Essential Oil at 1% of fresh forage (EO). On 100 d of ensiling, CL and FPE silages had lower (p<0.05) DM than CON silage. Additionally, FPE silage had higher (p<0.05) crude protein than CON silage. All silages with additives, except EO, had higher (p<0.05) neutral detergent fiber (NDF) than CON silage. Silage treated with CL, LB, and FPE had lower in vitro DM digestibility than CON silage, and silages treated with LB and FPE had higher in vitro NDF digestibility (IVNDFD) on 100 d of ensiling. The PFE silage produced the highest (p<0.05) lactate during ensiling period, while LB silage produced the highest (p<0.05) acetate. All inoculated silages had higher (p<0.05) LAB count than control silage. Only CL silage had higher (p<0.05) yeast count than control silage, while the other silages were not differ compared to CON silage. The aerobic stability was higher (p<0.05) in LB and FPE silages than in CON silage. In conclusion, FPE could be an alternative additive to increase IVNDFD, fermentation indices, and aerobic stability of barley silage.
The objective of this study was to investigate changes in drying yield, pH, water activity, microbial growth, and storage stability of bottom rounds of Hanwoo beef under four different dry-aging treatments (T1–T4) as temperature (2~4℃), relative humidity (65~86%) and dry-aging period (20~90 d). The drying yield decreased by 83.13–97.05% as the drying period increased. Among the four treatments, there were no significant differences in drying yield after 60 d of dry-aging. The total plate aerobic counts (TPC) increased by 1.07–4.39 log colony-forming units (CFU)/g as the dry-aging period increased. Of the four treatments, T4 at 40, 60, and 90 d had significantly higher TPCs than those observed for the other treatments on the same days (p<0.05). As the period of dry-aging increased, pH values increased by 5.35– 5.88 for knuckle and 5.34–5.62 for sirloin muscle, and water activity values decreased. For knuckle and sirloin muscle, the water activity values at 40 d and 60 d of T1 and T4 were significantly higher than those of the other treatments on the same days (p<0.05). The thiobarbituric reactive substances and volatile basic nitrogen values of the aged products increased as the dry-aging period increased. The results of this study showed that dry-aging conditions such as those in the T2 or T3 treatments (with a gradual increase in temperature and humidity) for less than 60 d would be best for yield, reduction of microbial growth and storage stability by dry the muscle surface quickly at the beginning period. Further research should include meat quality and economic analysis for these conditions that examines the benefits of these dry-aged products for the end processor.