Page 178 - Materials Chemistry, Second Edition

MODELING THE AGRI-FOOD INDUSTRY WITH LIFE CYCLE ASSESSMENT 163

environmental performance of a new product under development with the
products in that family/'
Starting from these general considerations, valid for all products, it is pos-
sible to review the particular issues regarding the choice of the functional unit
of an agri-food product. Some reviews of LCA studies of food and agricultural
products have shown first of all, in most cases, the choice of functional unit
is based on the mass or volume (Hospido, et al. 2010; Roy, et al. 2009; Schau &
Fet, 2008). However, this is very often a limitation of the study, as food prod-
ucts derive from complex production activities which employ different tech-
nologies that make them not exactly comparable, even when belonging to the
same type. In fact one of the main characteristics of food is to carry out vari-
ous functions via its various nutrients. Therefore, it may be useful to choose
a set of different functional units for the analysed system in order to evalu-
ate the variability of the results in terms of emissions. Regarding this there
are several studies that use multiple functional units chosen among mass of
products, energy or protein content, cultivated area, unit of livestock or eco-
nomic value (Martinez-Bianco, et al. 2011; Nemecek, et al. 2001; Seda, et al.
2010; Basset-Mens & van der Werf, 2003; Haas, et al. 2001; Hanegraaf, et al.
1998; Hayashi, 2006).
In a recent study, Petti et al. (Petti, et al. 2010) carried out a state-of-the-art
LC A of the wine industry. Starting from the analysis of the recent national and
international literature on wine LC A, the study investigated the main method-
ological choices made in wine LCA studies. In this study we have the confir-
mation that the functional unit is one of the main problems encountered when
an LCA of wine is carried out; in fact, most of the analysed studies consider a
standard amount of wine (usually 750 mL, which is the content of a commer-
cial bottle) as functional unit; the authors underline the need for an accurate
definition of functional unit, above all when different types of wine are com-
pared, because the functional performance of the products could not be easily
related to a certain amount of wine.
A critical review of LCA studies relative to the olive oil production (Salomone,
et al. 2010) suggests that it is necessary to pay particular attention to the dictions
of the products: the oils obtained by pressing olives are divided into extra-
virgin, virgin and current virgin olive oil which are not the same products.
Therefore the functional unit of 1 litre of extra virgin olive oil is not comparable
with simple olive oil. Furthermore, the analysis of the studies revealed the dif-
ficulty in comparing oils with completely different organoleptic characteristics
and yields.
These studies introduce a further element to consider in the choice of the
functional unit of an agri-food product: the product quality. Schau and Fet
(Schau & Fet, 2008) argue that the inclusion of quality aspects in the definition
of the functional unit is a more sophisticated way to choose. How can you
define the quality of a product? What is part of the product quality? Certainly
the quality of a food product depends on characteristics such as appearance,
flavor, availability and content of nutrients. The same content of nutrients may
be related to carbohydrates, fats, proteins, vitamins, minerals, energy content