Microbial quality, aflatoxin content and nutrient degradation of silver cyprinid stored at landing sites and in markets in Uganda

Figures & data

Figure 1. Geographical location of study area

Table 1. Proximate composition, microbial level, aflatoxin content and nutrient degradation of stored silver cyprinid from landing sites on Lake Victoria and markets in Kampala

Parameter	Variable	Samples from markets (n = 30)	Samples from landing sites (n = 40)	Reference level
Proximate composition	Moisture (%)	13.2 (12.1, 14.8)	20.1 (17.2, 24.5)*	12^∞
	Protein (%)	51.6 ± 4.8	53.1 ± 5.3
	Fat (%)	8.3 ± 2.5	9.2 ± 2.2*
	Ash (%)	13.7 ± 0.6	13.2 ± 3.5*
	Fe(mg/100 g)	18.5 ± 8.7	14.7 ± 5.4
Microbial quality	Total plate count (log cfu/g)	6.7 (5.8, 7.4)	6.6 (5.8,7.7)	5^∞
	Total Coliform (log cfu/g)	4.2 (3.0, 5.0)	3.6 (3.0, 4.6)*	0^∞
	Yeasts &Moulds (log cfu/g)	4.2 (3.5, 4.7)	4.7 (3.7, 5.4)*	4^∞
	Aflatoxin (ppb)^1	15.5 ± 2.2	14.5 ± 0.9	10^¥
Markers of fat and protein	TVBN (mgN/100 g)	10.1 ± 4.0	5.0 (3.4, 5.0)*	35^α
Degradation	FFA (mgKOH/g)	7.4 ± 1.4	3.6 (3.1, 4.3) *	3^¥
	TMA (mgN/100 g)	6.7 (3.4, 10.9)	2.5 (2.5, 7.6)*	15^α
	TBARs (µmolMDA/kg)	85.9 (65.2, 98.7)	61.1 (53.1, 75.4)*	111.0^£

Values are presented as means ±SD or median (Q₁, Q₃)

* = p < 0.05.

¹n = 5 from markets and n = 4 from landing sites, ^∞EAS (2014), ^¥Codex (2013), ^αHuss (1988) and ^£Schormuller (1968).

TVBN Total volatile basic nitrogen FFA free fatty acids TMA trimethyl amine TBARs thiobarbituric acid reactive substance.

Table 2. Proximate composition, microbial level, aflatoxin content and nutrient degradation of stored silver cyprinid from landing sites on Lake Victoria

Parameter	Variable	Landing sites	Kiyindi (n = 12)	Ssenyondo (n = 10)	Kasekulo (n = 8)	Maximum allowable limit
		Katosi (n = 10)
Proximate composition	Moisture (%)	22.7 ± 3.7^a	16.8 ± 7.2^b	19.7 ± 5.2^c	19.7 ± 8.8^bc	12^∞
	Protein (%)	52.4 ± 3.1^a	55.3 ± 9.0^a	52.5 ± 4.0^a	52.1 ± 2.0^a
	Fat (%)	9.8 ± 0.6^a	10.5 ± 2.2^a	7.3 ± 1.2^b	8.4 ± 2.8^b
	Ash (%)	11.3 ± 0.6^a	17.4 ± 4.7^b	13.1 ± 0.7^c	13 ± 2.7^c
	Fe (mg/100 g)	23.1 ± 0.1^a	10.3 ± 0.1^b	13.9 ± 0.2^c	11.5 ± 0.2^d
Microbial quality	TPC (log cfu/g)	6.7 ± 0.8^a	5.3 ± 1.0^b	7.3 ± 0.6^a	8.9 ± 1.4^c	5^∞
	TC (log cfu/g)	4.2 ± 0.7^a	2.4 ± 0.8^b	4.3 ± 1.1^a	4.1 ± 0.9^a	0^∞
	Y & M (log cfu/g)	5.1 ± 0.5^a	3.4 ± 1.1^b	5.2 ± 0.5^a	4.4 ± 1.0^c	4^∞
	Aflatoxins (ppb)^1	15.5 ± 0.1^a	15.1 ± 0.0^a	_	13.1 ± 0.1^b	10^¥
Markers of fat and	TVBN (mgN/100 g)	4.4 ± 0.7^a	3.9 ± 1.5^ab	7.0 ± 1.4^c	6.8 ± 6.5^c	35^α
Protein degradation	FFA (mgKOH/g)	3.2 ± 0.6^a	4.1 ± 1.1^a	3.6 ± 0.5^a	4.4 ± 1.2^a	3^¥
	TMA (mgN/100 g)	6.9 ± 4.3^a	2.1 ± 0.5^b	5.9 ± 4.7^ac	5.4 ± 2.7^ac	15^α
	PV (mEqO2/kg)	1.5 ± 0.9^a	4.9 ± 4.1^bc	2.8 ± 2.3^abc	4.5 ± 2.9^b
	TBARs (µmolMDA/kg)	59.0 ± 10.2^a	82.4 ± 27.6^b	57.2 ± 12.9^c	70.4 ± 34.4^abc	111.0^£

Values are presented as means ±SD or median (Q₁, Q₃).

* = p < 0.05.

¹n = 5 from markets, ^∞EAS (2014), ^¥Codex (2013), ^αHuss (1988) and ^£Schormuller (1968).

TVBN Total volatile basic nitrogen FFA free fatty acids TMA trimethyl amine TBARs thiobarbituric acid reactive substance.

Table 3. Moisture content, microbial level, aflatoxin content and nutrient degradation of stored silver cyprinid from different markets

Parameter	Variable	Markets	Kibuye (n = 6)	Nateete (n = 6)	Kalerwe (n = 6)	Nakawa (n = 6)	Maximum allowable limit
		Owino (n = 6)
Proximate composition	Moisture (%)	13.8 ± 1.6^a	13.3 ± 2.5^a	13.4 ± 2.9^a	12.5 ± 2.0^a	14.1 ± 1.6^a	12^∞
	Protein (%)	48.5 ± 8.9^a	50.3 ± 1.2^ab	54.1 ± 2.6^bc	56.3 ± 3.5^bc	48.1 ± 1.7^a
	Fat (%)	10.6 ± 0.8^a	9.2 ± 1.4^a	8.1 ± 0.9^a	8.7 ± 1.9^a	4.9 ± 2.7^b
	Ash (%)	13.6 ± 0.6^ab	13.9 ± 0.4^a	13.7 ± 0.6^ab	13.6 ± 0.3^ab	13.1 ± 0.3^b
	Fe(mg/100 g)	27.3 ± 0.7^a	21.4 ± 2.4^b	5.3 ± 0.1^c	20.1 ± 0.2^d	Not done
Microbial quality	TPC (log cfu/g)	7.3 (7.1,7.5)^a	7.7(7.1, 8.3)^a	6.4(5.6,7.3)^b	5.9(5.7,6.6)^b	5.7(5.0, 7.0)^b	5^∞
	TC (log cfu/g)	5.0 (4.5,5.6) ^a	4.8(4.2,5.1) ^a	4.4(3.6,5.1)^a	2.9(2.3,3.7)^b	2.8(2.3,4.3)^b	0^∞
	Y & M (log cfu/g)	4.4 (4.2,4.7)^a	4.7(4.2,5.2)^a	3.8(2.8,5.1)^b	3.7(3.0, 4.2)^b	3.6(3.2, 4.1)^b	4^∞
	Aflatoxins (ppb)^1	15.7 ± 0.1^a	18.0 ± 0.1^b	12.2 ± 0.4^c	16.2 ± 0.1^d	_	10^¥
Markers of fat and	TVBN (mgN/100 g)	10.4 ± 3.1^ab	11.2 ± 3.6^ac	11.9 ± 4.4^ac	8.4 ± 3.9^bc	8.6 ± 3.7^bc	35 ^α
Protein degradation	FFA (mgKOH/g)	10.2 ± 1.7^a	9.9 ± 2.2^a	8.1 ± 1.1^b	8.2 ± 1.0^b	7.9 ± 1.5^b	3^¥
	TMA (mgN/100 g)	19.3 ± 12.3^a	11.6 ± 9.3^ab	2.7 ± 1.2^b	5.2 ± 3.2^ab	7.1 ± 2.9^ab	15 ^α
	TBARs (µmolMDA/kg)	113.6 ± 33.1^a	73.8 ± 15.6^b	71.2 ± 21.4^b	80.3 ± 34.7^c	75.1 ± 52.0^b	111.0^£

Values are presented as means ±SD or median (Q₁, Q₃).

Superscripts indicate significant differences in groups at the level of ≤ 0.05.

¹n = 1 from each market.

^∞EAS (2014), ^¥Codex (2013), ^αHuss (1988) and ^£Schormuller (1968).

TVBN -Total volatile basic nitrogen, FFA- Free fatty acids, TMA- Trimethyl amine. TBARs- Thiobarbituric acid reactive substances.

EAS. (2014). East African standard dried fish Rastrineobola argentea-Specification DEAS 826:2014. ICS 67.120.30.

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Codex. (2013). Proposed draft standard for oils.

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Huss, H. H. (1988). Fresh fish quality and quality changes (Fisheries Series No. 29). Sagwan Press.

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Schormuller, J. (1968). Handbuch der Lebensmittelchemie (BandIII/2). Springer Verlag.

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