Food Biochemistry and Food Processing (2 edition)

BLBS102-c03 BLBS102-Simpson March 21, 2012 11:56 Trim: 276mm X 219mm Printer Name: Yet to Come

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Enzymes in Food Analysis

Isaac N. A. Ashie

Introduction

Analysis of the Major Food Components

Proteins and Amino Acids

Sugars

Other Food Components

Alcohol

Cholesterol

Antioxidants

Organic Acids

Analysis of Food Contaminants

Pharmaceuticals

Food Toxins

Endogenous Toxins

Process-Induced Toxins

Environmental Toxins

Enzymatic Analysis of Food Quality

Concluding Remarks

References

Abstract:Foods are primarily very complex matrices and there-

fore present an enormous technical challenge to the analyst whose

responsibility is to determine and establish the levels of various

components therein. A number of analytical tools, including en-

zymes, have therefore been developed through the years to meet this

challenge. The basis for enzyme use is its specificity that enables

selective, sensitive, and accurate determination of both macro- and

micronutrients in foods. The application of enzymes as an analytical

tool has, in recent years, been given a further boost by the devel-

opment of biosensors with improved robustness and versatility. In

this chapter, the application of enzymes (e.g., proteases, amylases,

lipases, oxidases, etc.) and the underlying principles for analysis of

food macro- and micronutrients including proteins, carbohydrates,

lipids, antioxidants, cholesterol, toxins, food contaminants (phar-

maceuticals, and food quality) are discussed.

INTRODUCTION

For centuries and prior to enzyme discovery and scientific under-

standing of its catalytic activity, humans had been inadvertently

tapping into the benefits of enzymes for the production of a va-

riety of foods. It is hard to think of food products like cheese,

bread, wine, and other alcoholic beverages today without con-

sidering the role of enzymes in their production. Since their

discovery, the unique characteristics of enzymes, such as their

natural origins and specificity, have been exploited in the pro-

cessing of a plethora of foods. These processes include (1) starch

liquefaction and saccharification using alpha amylases and amy-

loglucosidases, (2) conversion of dextrins to fermentable sugars

in brewing, (3) chill-haze prevention in the brewing industry us-

ing proteases, (4) juice clarification using pectinases, and (5) pro-

duction of high-fructose corn syrups by conversion of glucose to

its much sweeter keto-form, fructose, using glucose isomerase,

just to mention a few. Recent developments in the field of molec-

ular biology and protein engineering have enabled cost-effective

production of “customized” enzymes with tailored characteris-

tics that have further broadened the range of food applications

involving enzymes. For example, phospholipases for increasing

cheese yield and oil degumming, lipases for interesterification

of lipids as an alternative to chemical processes, carbohydrate

oxidases for lactose conversion to lactobionic acid used in the

transplant industry for organ preservation, and asparaginases for

acrylamide mitigation in foods are some of the emerging appli-

cations of enzymes in the food manufacturing process.

The broad range of enzyme classes used in the manufac-

ture of food products is a very good indicator of the challenges

presented to the food analyst, whose responsibility is to ana-

lyze the ingredients or components of different foods. Foods

are basically a complex matrix of edible ingredients, some of

which are present in high amounts (e.g., macronutrients such as

Food Biochemistry and Food Processing, Second Edition. Edited by Benjamin K. Simpson, Leo M.L. Nollet, Fidel Toldr ́a, Soottawat Benjakul, Gopinadhan Paliyath and Y.H. Hui.

©C2012 John Wiley & Sons, Inc. Published 2012 by John Wiley & Sons, Inc.

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