Shelf Life of Extra Virgin Olive Oil and Its Prediction Models

Table 2

Summary of shelf-life prediction models discussed in the review.

Model	Sample (bottles)	Storage condition	Chemical/physical analysis	Sensory analysis	Statistical analysis	Shelf-life prediction indicator	Ref.
1	37 Tuscan EVOO from 5 Lots	(i) Dark glass; (ii) In the dark (20°C)/uncontrolled light and temperature; (iii) 14/16/17/21 months; sampled every 2 months	FFA, PV, UV, polyphenol, alpha-tocopherol, tyrosol and hydroxytyrosol, secoiridoid aglycons, chlorophyll absorbance, carotenoid absorbance, induction time (120°C, 20 L/h)	(i) 12 trained panelists; (ii) Bitterness and astringency	(i) Sample classification: principal component analysis (PCA) and partial least-squares analysis (PLS) on Unscrambler 6.0 software package (Camo As, Trondheim, Norway); (ii) Comparison of regression lines: Statgraphics Plus 1.0 software package (Manugest KS Inc., Rockville, MD)	Time (in days) to reach of 2.1 : (i); (ii); (iii)	Pagliarini et al. (2000) [20]
2	46 experimental Spanish Picual and Hojiblanca EVOO and 30 commercial Picual and Hojiblanca EVOO	(i) Clear glass; (ii) Thermostated chamber (30°C)/in the dark (2°C); (iii) 6 months; sampled weekly during the first 70 days and every 15 days afterward	FFA, PV, UV, total phenols, o-diphenols, tocopherols, chlorophyllic and carotenoids, FAP and sterols, induction time (100°C, 10 L/h)	(i) 12 trained panelists; (ii) Highest quality (score 9) to lowest quality (score 1)	(i) Comparison of means: Duncan’s test; (ii) Analysis of variance and correlation: CoStat 2.10 software (CoHort Software, Berkeley, CA)	Time (in days) to reach of 0.25() according to initial stability ():	Gutiérrez and Fernández (2002) [35]
3	52 Greek Koroneiki virgin olive oil (VOO) from 1994 to 1997 for model development and 13 Koroneiki VOO from 1999-2000 for model validation	Stored at −22°C till analysis	FFA, PV, UV, total phenols, alpha-tocopherol, total chlorophylls, FAP and the ratio of unsaturated and saturated fatty acids (U/S), induction time (120°C, 20 L/h)		(i) Effect of the production year: linear regression, -test and variable selection; (ii) Possible collinearity among independent variables: variance inflation factor (VIF), PCA and singular value decomposition (SVD); (iii) Selection of analytical parameter affecting OSI the most: regressions, forward and backward selection, stepwise selection, Mallow’s index and Akaike’s information criterion (AIC); (iv) Statistical packages: SAS version 8 (SAS Institute Inc., Cary, NC), SPSS version 10 (IBM Corporation, Chicago, IL), and JMP IN version 3.1.7 (SAS Institute Inc., Cary, NC)		Psomiadou et al. (2003) [19]
4	Large EVOO sample size from Mediterranean areas from 1999 to 2001 for model development and 11 EVOO from 2002 for model validation	NP	63 chemical parameters including FFA, PV, UV, minor component content, lipid oxidation status and antioxidant activity	(i) 25 trained panelists; (ii) 18 sensory parameters including green olive aroma/flavor (e.g. bitterness), astringency, and pungency	(i) Fractional factorial design (FFD): Modde 8.0 software package (Umetri, Umea, Sweden); (ii) PCA and PLS: Unscrambler 7.8 software package (Camo AS, Oslo, Norway)	EVOO degradation parameter value () as a function of FFA (), oleic acid content () and bitterness score ():	Zanoni et al. (2005) [10]
5	432 Portuguese organic EVOO	(i) PET/PVC/glass bottle; (ii) Covered with aluminum foil inside fiberboard boxes/under fluorescent light at 15/30/40°C with relative humidity of 60%; (iii) 12 months; sampled monthly	Hexanal	NP	(i) Determination of differences between treatments for the hexanal evolution rate: SAS 8.2; (ii) Separation of the means of GC areas: Tukey test and Duncan test; (iii) Model development: nonuniform finite-difference scheme with an upwinding numerical algorithm (Newton method for nonlinear systems)	Probability for the olive oil to reach the end of its shelf life during a certain period of time ():	Coutelieris and Kanavouras (2006) [34, 36]
6	Seven Spanish Cornicabra VOO	(i) Opened amber glass; (ii) In the dark at 25/40/50/60°C; (iii) sampled after 93/41/34/19 weeks	PV, UV, FAP, phenolic compounds, tocopherols, induction time (100°C, 10 L/h)	NP	(i) Differences between treatments: Duncan test on SPSS version 14; (ii) Linear and nonlinear regression: GraphPad Prism 4.02 (GraphPad Software, Inc., San Diego, CA); (iii) Oxidation and antioxidant degradation rates: calculated from the slopes of respective concentration versus time curve; (iv) Effect of temperature on rates of oxidation: Arrhenius equation	Time (in weeks) to reach of 2.5 at a mild temperature (T ≤ 60°C):	Mancebo-Campos et al. (2008) [23]
7	Six single-cultivar VOO	(i) Amber glass; (ii) In the dark at room temperature/15°C; (iii) 12 months; sampled monthly	Chlorophyll pigments (pheophytin a and pyropheophytin a)	NP	(i) Differences between means: one-way ANOVA; (ii) Post hoc comparison: Brown and Forsythe test [37]; (iii) PCA, PLS, and nonlinear regression: Statistica 6.0 and Statgraphics Centurion XV for Windows (StatSoft Inc., Round Rock, TX)	The percentage of pyropheophytin a (% PPP) over time ():	Aparicio-Ruiz et al. (2012) [16]
8	Nine olive oil samples	Stored at 4°C until analysis	FFA, PV, total tocopherols and total phenols, total polar compounds, conjugated diene value, ratio of mono- and poly-unsaturated fatty acids (M/P ratio), and induction time (100/110/120/130°C, 25 L/h)	NP	ANOVA and regression analyses: MStatC (Michigan State University, East Lansing, MI) and SlideWrite (Sigma Aldrich, St. Louis, MO)	Calculate shelf life at 50°C (SL50) as a function of induction time (OSI):	Farhoosh and Hoseini-Yazdi (2013) [25]
9	A wide range of commercial olive oil samples for model development and 118 olive oil and 20 EVOO for model evaluation	(i) Dark glass; (ii) In the dark at 18 ± 2°C; (iii) 30 months; sampled when estimated best before date was reached	FFA, PV, UV, PPP, DAGs, and induction time (110°C, 20 L/h)	(i) 12 trained panelists; (ii) The median values of defect, fruitiness, bitterness, and pungency	NP	Best before date (in months) from the lowest value obtained from induction time, DAGs, FFA Factor (derived from FFA) and PPP: FFA factor = 1.7% (if FFA < 0.4%); 2.1% (if FFA > 0.4% and <0.6%); or 2.5% (if FFA > 0.6%)	Guillaume and Ravetti (2016) [18]
10	36 EVOO	(i) Amber glass; (ii) In the dark/exposed to natural and artificial light at room temperature (17–25°C); (iii) 12 months; sampled after 0/3/6/9/12 months	FFA, PV, UV, induction time; electronic tongue signal profile	(i) 4 trained panelists; (ii) Olfactory sensations, gustatory-retronasal sensations, and final olfactory-gustatory sensations	See Table 10	3 best linear discriminant analysis (LDA) and simulated annealing (SA) prediction models	Rodrigues et al. (2017) [38]

: not provided.