Green technologies for production of oils rich in n-3 polyunsaturated fatty acids from aquatic sources

Figures & data

Scheme 1. Overview of the green processes with higher potential for the production of oils rich in n-3 PUFAs from aquatic sources. MW, microwave; US, ultrasound; SFE, supercritical fluid extraction; PLE, pressurized liquid extraction.

Scheme 2. Methods and technologies investigated for each processing step in oil from aquatic sources. (C) Conventional method of the step. MW, microwave; US, ultrasound; LAB, lactic acid bacteria; PLs, phospholipids; FFAs, free fatty acids; MASE membrane-assisted solvent extraction; SPD, short-paths distillation; PUFAs, polyunsaturated fatty acids; POPs, persistent organic pollutants; MUFAs, monounsaturated fatty acids.

Table 1. A summary of different methods for oil extraction from different aquatic sources.

	Sample	Extraction method	Oil yield (%)	SFA (%)	MUFA (%)	PUFA (%)	PV (mEq O2·kg^−1)	AV (mg·g^−1)	Iodine value	Reference
Physical	6 Fish species muscle	Bligh and Dyer	1.3–6.1	388–1823^a	205–2237^a	323–646^a				Ozogul et al. (2018)
		Soxhlet	0.2–3.9	30–1197	16–1305	14–381
		MAE	1.4–2.8	542–990	325–536	184–524
		UAE	1.6–5.1	492–1400	295–2222	243–583
	Tilapia fillets	Folch	2.3	38.2	43.9	17.9	1.8			Costa and Bragagnolo (2017)
		MAE	2.3	38.2	43.9	17.9	0.2
	Crypthecodinium cohnii	Soxhlet	4.8	47.5	0.2	49.9				Cravotto et al. (2008)
		UAE	25.9	47.6	0.2	49.3
		MAE	12.5
Enzymatic	Catfish muscle	Bligh and Dyer	25.2	48.8	34.2	10.6				Senphan and Benjakul (2015)
		10-CPE	23.5	48.8	35.2	10.4
		10-Alcalase	24.3	48.9	35.8	10.2
		Wet reduction	24.3	48.2	35.7	10.3
	Yellowfish tuna by-products	Bligh and Dyer		27.4	70.8	1.8	10.8		2.3	de Oliveira et al. (2017)
		Wet reduction		44.4	24.5	31.1	10.5		4
		Alcalase		33.3	27.6	39.1	5.1		2
	Salmon head	High-temperature	71.1	19.7	39.9	34.5	9.2	1.3		Głowacz-Różyńska et al. (2016)
		Low-temperature	71.5	19.6	42.5	32.7	2.5	0.2
		Alcalase	72.1	20.7	40.1	33.6	1.6	0.7
	Labeo rohita head	Control	55.9	34.4	24.9	37.6	136^c	5.6 < AV < 8.0		Bruno, Kudre, and Bhaskar (2019)
		MW^b	60.5–69.8	34.6	24.8	37.5	187^c	8
		US^b	58.7–68.1	31.5	26.5	39.3	132^c	5.6 < AV < 8.0
		Heating^b	32.0–32.3	32.9	25.6	38.3	79^c	5.6
	Chlorella vulgaris	US + 5 types of enzymes	10–35							Liang, Zhang, and Cong (2012)
	Nannochloropsis	6 types of enzymes	15–35							Zuorro et al. (2016)
SFE-CO2 and PLE	Indian mackerel skin	Soxhlet	53.6	16.7	7.7	59.6				Sahena et al. (2010)
		SFE-CO2 continuous	24.7	18.2	7.7	56.3
		SFE-CO2 with co-solvent	53.2	16.2	7.5	59.7
		SFE-CO2 soaking	52.8	15.9	7.5	59.7
		SFE-CO2 pressure swing	52.3	16.4	7.4	60.5
	Trout by-products	Soxhlet	41–70	24.3–27.9	72.1–75.7					Fiori et al. (2012)
		SFE-CO2	36–79	24.7–27.4	72.6–75.3
	Carp by-products	Soxhlet	45–50	20.8	45.3	33.4				Kuvendziev et al. (2018)
		SFE-CO2	28–52	19.4	46.6	34.1
	Arthrospira maxima	Bligh and Dyer	100	41	10	48				Mendes, Reis, and Palavra (2006)
		SFE-CO2	40	13	27	60
		SFE-CO2 + ethanol	32	16	17	62
	C. cohnii	Bligh and Dyer	19.9	41.8	8.0	50.0				Couto et al. (2010)
		SFE-CO2	8.6	48.5	8.4	43.1
	Isochrysi sp,	Folch	25.4							He et al. (2019)
		PLE with n-hexane	34.4
		PLE with 90% ethanol	41.5	8.4^e	5.4^e	10.3^e
SFE-CO2 and enzymatic	Sturgeon muscle	Wet reduction	52.5^d	25.3	44.2	30.7	4.2	3.6		Hao et al. (2015)
		Protease	83.6^d	25	43.8	31.9	3.2	3.3
		Amino method	38.7^d	24.9	44.3	31.8	3.1	4.5
		SFE-CO2	97.3^d	20.3	45.6	33.7	2.5	0.8
	Tuna livers	SDEE	98.6^d	42.7	24.5	32.8	1.8			Fang et al. (2018)
		Wet reduction	56.8^d	47.4	23.3	29.3	1.6
		Protease	85.3^d	47.6	23	29.4	3.1
		SFE-CO2	98.5^d	42.9	24.3	32.8	3.9
Fermentation	Carp viscera	Wet reduction	20	40.5	48.9					Rai et al. (2010)
		Natural fermentation	85	39.9	49.2				113.3
		LAB 1	84	39.6	50.1				117.8
		LAB 2	83	39.7	50				117.8
	Giblel carp	Natural fermentation		35.3	31.4	19				Özyurt et al. (2019)
		Acid fermentation	82.2	35.7	30.2	18.3	4.5	17.8
		LAB strains	75.9–87.4	35.8–36.5	30.7–31.7	17.7–18.4	1.1–<4.5	5.7–10.3
	Kluzinger’s ponyfish	Natural fermentation		23.2	37.1	15.4
		Acid fermentation	76.8	21.9	40	14.6	3.4	15
		LAB strains	70.1–76.8	22.2–23.0	14.6	14.5–15.5	1.8–<3.4	5.7–10.3

MAE, microwave assisted extraction; UAE, ultrasound assisted extraction; CPE, crude protease extract; MW, microwave; US, ultrasound; SDEE, subcritical dimethyl ether extraction; LAB, lactic acid bacteria; PLE, pressurized liquid extraction.

^a mg/100 g of fish.

^b Pretreatment followed by enzymatic extraction.

^c PV calculated with the ferric thiocyanate method (Chaijan et al., 2006) .

^d % of extraction considering Soxhlet 100%.

^e wt% of biomass.

Table 2. Degumming processes applied for phospholipids (PLs) removal.

Sample	Degumming process	Lipid yield (%)	SFA (%)	MUFA (%)	PUFA (%)	PV (mEq O2·kg^−1)	AV (mg·g^−1)	Acidity (%oleic acid)	Phosphorous content (ppm)	Reference
Sardine oil	Crude	8.3	41.0	29.2	26.5	11.9	16.2	4.4		Chakraborty and Joseph (2015)
	Phosphoric acid	86.0	40.2	29.5	26.0	7.2	13.6	7.9
	Acetic acid	93.1	40.6	29.7	26.4	8.0	14.1	7.0
	Oxalic acid	90.1	40.8	29.5	26.3	7.6	14.7	6.0
	Citric acid	92.6	40.4	28.9	26.2	8.3	15.0	5.6
Crude corn oil	Crude								495	Turetkan et al. (2018)
	Citric acid								55
	Enzymax process								6
	Direct enzyme								6
Soybean oil	Crude							0.8	875	Sampaio et al. (2015)
	Citric acid							0.3	32
	Citric acid + enzyme							0.8	1
Corn oil	Crude							2.3	951	Sampaio et al. (2019)
	Water								67
	CP + enzyme								27
	CC + enzyme								26
Soybean oil	Water								128	Li et al. (2016)
	Citric acid								35
	PLA1								63
	Bi-PLA1								10
	Im-bi-PLA1								7
Soybean oil	Crude oil					3.1	2.3	1.7		More and Gogate (2018)
	Enzymatic					0.3	0.8	1.3	Reduce 94.1%
	UA + enzymatic					0.3	0.7	0.7	Reduce 98.4%
Rapeseed oil	Crude								5655	Szydłowska-Czerniak and Łaszewska (2017)
	Acid								268
	EDTA								74
Five vegetable oils	Crude								43–141	Hafidi, Pioch, and Ajana (2005)
	H3PO4 + NaOH + membrane								1.5

CP, caustic pretreatment; CC, chemical conditioning; EDTA, ethylenediaminetetraacetate; PLA₁, phospholipase A₁; Bi-PLA₁, bio-imprinted phospholipase A₁; Im-bi-PLA₁, immobilized bio-imprinted PLA₁, UA, ultrasound assisted.

Table 3. Deacidification processes for free fatty acids (FFAs) removal.

Sample	Deacidification process	Oil yield (%)	SFA (%)	MUFA (%)	PUFA (%)	PV (mEq O2·kg^−1)	AV (mg·g^−1)	Acidity (%oleic acid)	Acid value (mg KOH·g^−1)	Iodine value	Reference
Rice bran oil	NaOH	80.2				2.0		0.4			De and Patel (2010)
	Na2CO3	83.5				3.0		0.7
	NaHCO3	85.8				3.5		0.8
Tuna oil	Crude pretreated AC				32.1	3.5	44.4	3.5	10.2	187	Wang et al. (2012)
	Lipase + ethanol + SPD				82.2	7.6	26.4	7.6	0.4	350
	Lipase + glycerol + SPD				80.1	8.5	11.3	8.5	1.1	345
Sardine oil	Crude		71.5	11.3	16.4			5.6			Charanyaa, Belur, and Regupathi (2017)
	Solvent	70	74.2	10.8	17.5			1.1
	Membrane + solvent	93	—	—	—			1.1
Palm oil	Betaine monohydrate-based DES							49.4% extraction of palmitic			Zahrina et al. (2018)

AC, activated carbon; SPD, short-path distillation, DES; deep eutectic solvent

Table 4. Bleaching processes of fish oil using various combinations of bleaching agents.

Sample	Bleaching process	SFA (%)	MUFA (%)	PUFA (%)	PV (mEq O2·kg^−1)	AV (mg·g^−1)	Acidity (%oleic acid)	Iodine value	TOTOX	Hue angle	Chroma	POP (ng·kg)		Reference
Sardine oil	Neutralized				2.4	77.0	0.17		81.7	80.4	98.1			García-Moreno et al. (2013)
	Clay				0	21.8	0.18		21.8	89.2	81.8
Carp oil	Crude	27.4	41.3	26.0	4.0		7.3	115			16^a			Monte et al. (2015)
	BE + AC	27.3	41.3	25.9	2.5		0.9	114			11.4^a
Sardine oil	Neutralized	40.2	29.0	25.6	6.1	10.0	3.2		22.2	79.3	44.4			Chakraborty and Joseph (2015)
	AC (5%)				4.4	9.4	2.8		18.2	84.6	39.0
	KA (5%				6.5	10.5	3.4		23.4	81.1	42.1
	FE (5%)				5.0	9.5	3.2		19.6	84.7	40.0
	CE (5%)				6.0	9.9	3.4		22.0	79.5	41.3
	CH (5%)				5.7	9.9	3.4		21.4	83.0	40.9
	AC + FE	38.2	28.5	26.6	3.7	9.4	2.9		16.7	38.1	84.6
Canola oil	Neutralized	7.2	47.9	32.5	12.6	5.5			30.6					Icyer and Durak (2018)
	Bleaching earths	10.5	46.5	32.7		9.9–18.6			23.6–31.1		6% reduction in yellow
	UA-bleaching	9.8	48.6	32.4	7.0–7.9	10.6–20.0			26.5–35.5		6%–34% reduction in yellow
Sprat oil	Crude				1.8	10.0			13.6			PCDD	7.83	Oterhals et al. (2007)
												PCDF	27.4
												PCB	18,560
	AB				1.6	6.6			9.8			PCDD	8.57
												PCDF	30.2
												PCB	20,588
	AB + AC				1.4	6.5			9.3			PCDD	nd
												PCDF	0.358
												PCB	19,168
Salmon oil	11 silicon-based											No signifcant elimination		Ortiz et al. (2011)
	9 carbon-based											PCDD	99%
												HCB	70%
												PCB	27%
Sprat oil	Crude				1.8	20.4			14.0					Oterhals and Berntssen (2010)
	AB				1.7	6.0			9.4
	SPD				0.7	5.5			6.9			76% reduction
Fish liver oils	Crude	13.9, 24.8	46.5, 44.0	15.6, 23.5	6.3, 10.3	20.1, 21.5	0.5, 13.8		30.2, 42.2					Oliveira and Miller (2014)
	SPD	14.7, 24.9	51.0, 43.8	14.2, 23.7	0.1, 2.4	13.8, 4.6	0.1, 0.0		14.1, 9.4
Menhaden oil	SCE											PCDD	35%	Kawashima et al. (2009)
												PCDF	84%
												PCB	93%
	SCE + AC											PCDD	80%
												PCDF	No change
												PCB	No change

AB, alkali bleached; AC, activated carbon, KA, kaolin; FE, Fuller’s earth; CE, cellulose powder; CH, chitin; SPD, short-path distillation; PCDD, polychlorinated dibenzo-p-dioxins; PCDF, polychlorinated dibenzofurans; PCB, polychlorinated biphenyls; HCB, hexachlorobenzene.

^a Values obtained from Lavibond color (30 Y, R).

Table 5. Deodorization processes employed in fish oil refining.

Sample	Deodorization process	SFA (%)	MUFA (%)	PUFA (%)	PV (mEq O2·kg^−1)	AV (mg·g^−1)	Acidity (%oleic acid)	Iodine value	AI (mg KOH·g^−1)	SV (mg KOH·g^−1)	Volatiles (%)	Reference
Fish oil	5 types of zeolites										Deodorization 20%–60%	Chung and Lee (2009)
Processed tuna and anchovies	Crude	36.9	28.9	34.2	3.5			118.5	0.3	221.6	93.2	Song, Zhang, et al. (2018)
	SPD	32.0	31.8	36.2	3.7			132.8	0.1	222.1	11.7
	Steam distillation	32.4	31.9	36.3	3.7			130.2	0.1	223.3	94.1
	GTP treatment	29.6	32.2	38.3	1.9			125.3	0.2	224.5	84.5
	L-L (alkaline ethanol)	29.5	32.2	38.3	2.9			127.4	0.2	223.8	72.5
	Activated clay	34.2	29.2	36.1	2.1			124.1	0.2	224.0	90.3
	Zeolites	34.6	29.3	35.8	2.3			126.6	0.2	223.6	97.5
	Diatomite	34.8	29.5	35.7	2.2			120.8	0.2	220.5	78.9
Tuna oil	Crude	15.8	35.3	49.0	1.7	0.3		186.0			125.2 (OAV)	Fang et al. (2018)
	Steam	18.0	34.9	47.3	1.8	0.3		182.0			75.1
	Nanofiltration (360 Da)	15.3	35.2	49.6	1.1	0.2		185.0			17.5
Squid oil	Crude	24.8	29.4	45.9	1.8	0.4		180.0			129.8
	Steam	27.7	28.7	43.4	2.0	0.4		176.0			68.1
	Nanofiltration (360 Da)	23.8	29.5	46.8	1.2	0.3		181.0			10.1

SPD, short-path distillation; GTP, green tea polyphenols; OAV, odor active value.

Scheme 3. (a) The rationale to design the process protocol to obtain high purity n-3 enriched monoacylglycerols from low n-3 PUFA oil by using non-regiospecific, non-n-3 PUFA preferential lipase. (b) The practical results of representative reactions as shown by spectra of ¹³C-NMR analysis (Adapted from He, Li, Kodali, Chen, et al. (2017)).

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