1. A COMPARISON OF MINERAL CONTENT IN ORGANICALLY AND
CONVENTIONALLY GROWN ALMONDS
Jill Vrastil; Wendy Reiboldt, PhD; Cheryl Rock, PhD; Selena Nguyen-Rodriguez, PhD
California State University, Long Beach
Abstract:
The current debate over whether conventional or organic farming is superior has produced an abundance of literature, however, only a small portion is devoted to mineral composition of foods ready for consumption.
The purpose of this study was to compare mineral content in conventional versus organic foods, specifically, almonds. Almonds are a convenient and popular food and are part of a healthful diet.
Three samples each of conventional and organic almonds were lab tested for calcium, iron, magnesium, potassium, and zinc quantites.
Results of the analyses showed no significant differences in conventional versus organic almonds for calcium (p = .359), iron (p = .368), magnesium (p = .921), potassium (p = .129), or zinc (p = .875).
Although this data suggests little difference in mineral content between the conventional and organic group, the small sample size (n = 6) provides unsubstantial evidence that a difference may not exist in larger samples.
INTRODUCTION
BACKGROUND
METHODOLOGY
SUMMARY & CONCLUSION
Differences in conventional and organic farming:
Consumer and Farmer Perceptions
Ecological and Environmental Impact
Pesticides and Pathogens
Soil Composition
Food Composition
Purpose of this study:
Compare conventional and organic food products by testing mineral content
Setting up the study:
Almonds are nutrient dense, convenient, and abundant
Five essential minerals of interest: calcium, iron, magnesium, potassium, and zinc
Limited research investigating mineral composition between conventionally and organically farmed foods
Mineral content more reliant on soil composition based on location and farming practices, such as fertilizing and tilling (Pimentel et al., 2005)
Review of the literature did not strongly indicate that differences would be found in conventional vs. organic almonds
Samples
Three packages conventionally grown almonds
Three packages organically grown almonds
Purchased in southern California markets
Procedure
Mineral analyses conducted using Inductively Coupled Plasma (ICP) - Atomic Emission Spectrometry (AES)
Detection limits for all minerals were 5.0 parts per million (PPM), except zinc, which had a detection limit of 1.0 PPM
Results reported as mineral content in milligrams (mg) per 100 g of almonds
Statistical Analyses
SPSS Version 24.0: Independent-Samples t- Tests (significance level of p = 0.05)
Assumption of homogeneity of variance tested using Levene's test (significance > .05)
Summary
No statistically significant difference found when comparing quantity of calcium, iron, magnesium, potassium, or zinc between conventionally grown and organically grown almonds
Small effect size found in iron
Medium effect size found in calcium and potassium
No effect size found in magnesium or zinc
High variability within groups
Limitations
Small sample size (6 total)
Little known about specific farm practices, only conventional or organic label
Almond age and variety unknown
Limited growing regions available
Conclusion
Farming practices may be nutritionally equivalent when considering mineral content
Mineral content likely dependent on soil composition and fertilization methods
Results support the reevaluation and redefining of modern farming practices
Implications for the Future
Samples should be accompanied by qualitative analysis to account for possible differences in mineral content
More comprehensive testing could paint a better picture of overall nutritional content, such as adding vitamin and macronutrient quantities
California produced approximately 2,002,742 tonnes of almonds in 2016
(Food and Agricultural
Organization, 2017).
PURPOSE & HYPOTHESES
Purpose of this study
Specifically, this study compared mineral content in samples of conventional and organic almonds.
Hypotheses
H0 1: No significant difference in calcium content between organic and conventional almonds.
H0 2: No significant difference in iron content between organic and conventional almonds.
H0 3: No significant difference in magnesium content between organic and conventional almonds.
H0 4: No significant difference in potassium content between organic and conventional almonds.
H0 5: No significant difference in zinc content between organic and conventional almonds.
RESULTS
Results of the Mineral Analyses:
Results of Independent Samples t-Tests:
Almonds,
scientifically
known as
Prunus
dulcis,
are the
number
one produced tree
nut in the world
(Chen, Lapsley, & Blumberg, 2006).
t = ,
p = .129
r = 0.481
t = -.462,
p = .668
r = 0.237
CONTACT
t = 1.035,
p = .359
r = 0.460
t = .110,
p = .921
r = 0.074
JILL VRASTIL
Phone: (310)