| As a state protected local elite swine, Rongchang swine has a reputation for good adaptability, stable genetic performance, high lean percentage, excellent meat quality, and wide geographic distribution in the production area. In this paper, nutrition and meat quality characteristics were determined. Skatole, with the unpleasant odour, was analyzed by high performance liquid chromatography (HPLC). And volatile compounds of both castrated swine and male swine were analyzed by gas chromatograph-mass spectrum(GC-MS). The main results were as following:1 Moisture content of muscle in 4 positions of Rongchang swine(73.54±0.68%,73.46±0.77%,74.13±0.42%,73.35±0.22%) were not significant differences(P>0.05). The intramuscular fat contents were 2.41±0.35%,2.61±0.37%,2.28±0.26% and 4.8±0.21% respectively. There was not significant differences among NO.1, NO.2 and NO.3(P>0.05). However NO.4 had significant differences compared with the others (P<0.05). Protein contents of Rongchang swine (%) (22.06±0.39,22.41±0.38,22.12±0.12,21.46±0.23) were not significant differences (p>0.05). The pH value of muscle(pH1=6.22±0.18, pHu=5.57±0.14) decreased slightly in 24h after slaughtering. There was no significant differences among the values of Hunter's L*, a* and b* of No.224h after slaughtering.compared with those 45min after slaughtering. The color stability was good within 24h after slaughtering. The rate of water loss of No.2 was low(12.17±1.26%).2 Skatole content in Rongchang swine was analyzed by HPLC. DIONEX Acclaim 120 C18 column (4.6 mm×250 mm,5μm) was used at 30℃. Mobile phase was 60%Acetonitrile 40%wate with flow rate of 1 mL/min. Excitation wavelength was 281 nm while emission wavelength was 353 nm. Working curve of standard skatole was drawn with a good linear relationship. Both recovery and precision were good.3 Skatole content in fat of No.1, No.2 and No.3 (ng/g) (3.4434±0.1276,11.5035±0.5464,2.9727±0.1142) were significant differences (p<0.05) when Rongchang swine was 80kg weight. Skatole content in fat of No.3 and NO.1 were not extremely significant differences (P>0.01), however, comparing with those of No.2, differences were extremely significant(P<0.01). Skatole content in muscle of No.1, No.2 and No.3 (ng/g) (0.7581±0.0817,1.1513±0.0823,0.2827±0.0785) of Rongchang swine(80kg weight) were significant differences (P<0.05). No.l and No.2 were not extremely significant(.P>0.01), but comparing with No.3, differences were extremely significant (P <0.01). Skatole content in both muscle and fat were lower than the threshold of the unpleasant odour. 4 Skatole content in fat and muscle of No.l, No.2 and No.3 were significant difference (P< 0.05) when Rongchang swine was 40kg weight. Comparing with No.l and NO.2, Skatole content in muscle of NO.3 had differences were extremely significant (.P<0.01),while No.2 and NO.1 had no extremely significant difference (P>0.01). Skatole content in fat of NO.2 were extremely significant differences, as compared with No.l and NO.3(P<0.01). And Skatole content in fat of No.3 and NO.1 had no extremely significant difference (P>0.01).Skatole content in fat and muscle of No.l, No.2 and No.3 were significant difference when Rongchang swine was 50kg weight (P<0.05). Skatole content in muscle of NO.1, NO.2 and NO.3's differences were extremely significant (P<0.01).Skatole content in fat of No.3 were extremely significant difference comparing with No.1 and NO.2 (P<0.01),however, Skatole content in fat of NO.1 and NO.2 were not extremely significant difference (p>0.01).Comparing with Rongchang swine' weight of 40kg and 50kg, the skatole content in the same position were significantly differences (P0.05). Skatole content in all parts muscle and fat were lower than the threshold of the unpleasant odour.5 Skatole content in muscle and fat were (ng/g) 1.1102±0.3203,4.1014±0.4567 in No.2 from PIC pig. It is lower than the skatole content in No.2 when Rongchang pig was 80kg. Skatole content in muscle had no significant differences between PIC pigs and Rongchang pigs (P> 0.05), Skatole content in fat was extremely significant difference between PIC pigs and Rongchang pigs (P<0.01)。6 Skatole content in muscle were (ng/g) 1.6738±0.6162,2.4403±0.3071,0.8501±0.1765 in No.1, No.2 and No.3 from fresh pork, skatole content in fat were (ng/g) 28.5001±0.9739,63.5145±1.8880,15.9848±1.0084. Skatole in muscle and fat from fresh pork were higher than those in Rongchang pigs, comparing with the same part in Rongchang pig, and they were extremely significantly differences(p<0.01).7 There were 89 kinds of volatile flavor compounds were analyzed in No.3 muscles of castrated Rongchang porket, and could be divided into 11 types as follows:12 kinds of aldehydes, 15 kinds of acids,4 kinds of alcohols,7 kinds of ketones,20 kinds of hydrocarbons,9 kinds of esters, 12 kinds of amino and nitrogen compounds,5 kinds of furans and oxygen heterocyclic compounds, 3 kinds of benzene and derivatives,1 kind of sulphocompound and 1 kind of indole. There were 82 kinds of volatile flavor compounds were analyzed in No.3 muscles of uncastrated Rongchang porket, and could be divided into 7 types as follows:60 kinds of hydrocarbons,6 kinds of aldehydes,3 kinds of alcohols,1 kind of ketone,10 kinds of esters,1 kind of furans and oxygen heterocyclic compounds and 1 kind of steroide.8 The highest content of the volatile flavor compounds detected in castrated Rongchang pig was hexanal; In detected volatile flavor compounds of uncastrated Rongchang pig, the highest content was hydrocarbon, followed by esters, and aldehydes. In addition, Characteristics of compounds of uncastrated Rongchang pig were detected, which was androstane, and whose relative content was 0.03%。9 From No.3 of castrated and uncastrated Rongchang pig, we have confirmed that some detected compounds were aroma type。They were Hexanal (fragrance-hay scented), Octanal (fresh-the new Hong), Nonanal (fragrance), E-formaldehyde (fruity, bread Hong)。In castrated Rongchang pig, there were3-hydroxy-2-butanone (sweet, dairy products Hong), acetic acid (vinegar Hong), benzoic acid (balsam gas), ocimene (grass Hong, tropical fruity)。In Rongchang full boar, there were 2-pentyl-furan (Class ham Hong),1-pentanol (sesame oil flavor),1-hexanol (fruity), etc.
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