Complying with food regulations and, more importantly, quality standards, requires practical and reliable methods to estimate a product’s shelf life. Emphasizing the importance of the consumer’s perception of when food has reached the end of its shelf life, Sensory Shelf Life Estimation of Food Products provides a tool for adequately predicting sensory shelf life (SSL).

Features:

• Explains how to design a shelf life estimation experiment
• Develops the application of survival analysis statistics to SSL prediction using acceptance/rejection data obtained from consumers
• Presents instructions, code and downloadable example files to be used with the freely available R-statistical package
• Details the cut-off point methodology as an alternative to survival analysis.
• Covers non-linear and survival analysis modeling of Arrhenius’ equation to obtain adequate predictions of activation energies
• Includes an R-function to perform a non-linear regression to better estimate activation energy
• Describes extensions of survival analysis statistics to other food applications

Contents

Introduction

• Sensory Shelf Life Definition
• Labeling Regulations
• Shelf Life of Foods Is Sensory Shelf Life
• Importance of the Consumer in Defining Food Quality
• Books on Shelf Life of Foods

Principles of Sensory Evaluation

• Definition of Sensory Evaluation
• Sensory Analysis: Trained Panels versus Experts
• General Requirements and Conditions for Sensory Tests
• Physiological Factors
• Psychological Factors
• Sensory Evaluation Methods

Design of Sensory Shelf-Life Experiments

• Initial Considerations
• Approximations of Shelf-Life Values

Survival Analysis Applied to Sensory Shelf Life

• What is Survival Analysis?
• Censoring
• Survival and Failure Functions
• Shelf Life Centered on the Product or on Its Interaction with the Consumer?
• Experimental Data Used to Illustrate the Methodology
• Censoring in Shelf-Life Data
• Model to Estimate the Rejection Function
• Calculations Using the R Statistical Package
• Interpretation of Shelf-Life Calculations
• An Additional Example
• Should Consumers be Informed?
• Is There a Way to Deal with Totally New Products?

Survival Analysis Continued: Number of Consumers, Current Status Data, and Covariates

• Number of Consumers
• Current Status Data
• Introducing Covariates in the Model

Cut-Off Point Methodology

• When is the Survival Statistics Methodology Difficult to Apply?
• Basics of the Cut-Off Point Methodology
• Approaches in Establishing a COP
• Methodology to Measure the COP
• Instrumental Cut-Off Points
• Caveats for Using COP Methodology

Accelerated Storage

• Arrhenius Equation and Activation Energy
• The Use of Q10
• Survival Analysis Accelerated Storage Model
• Potential Pitfalls of Accelerated Shelf-Life Testing
• Conclusion on Accelerated Testing

Other Applications of Survival Analysis in Food Quality

• Consumer Tolerance Limits to a Sensory Defect
• Optimum Concentration of Ingredients in Food Products
• Optimum Salt Level in French Bread
• Internal Cooking Temperature of Beef
• Optimum Ripening Times of Fruits

Index

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