QUALITY ASSESSMENT OF SOUTHLAND CULTIVAR PEACHES [600265]

QUALITY ASSESSMENT OF 'SOUTHLAND' CULTIVAR PEACHES
ACCORDING TO CERTAIN TECHNOLOGICAL FACTORS
OF CULTURE AND STORAGE

Constan܊a ALE XE1, M. VINTILĂ1, Simona POPESCU1, Veronica TĂNASA1,
Liana -Melania DUMITRU2, Gh. LĂMURANU2, Lenu܊a CHIRA3

1Research and Development Institute for Processing and Marketing of the Horticultural Products,
1A Intrarea Binelui, District 4, 042159, Bucharest, Romania,
Phone [anonimizat], fax [anonimizat], E-mail: [anonimizat]
2Research Station for Fruit Growing (R.S.F.G) Constan܊a, 1 Pepinierei, 907300, Valu lui Traian,
Romania, Phone /Fax.+4024123187, E-mail: [anonimizat]
3University of Agronomic Sciences and Veterinary Medicine of Bucharest, 59 Mără܈ti, District 1,
011464 Bucharest, Romania, Phone: +40 21 318 25 64/232, Fax: + 40 21318 28 88
E-mail: [anonimizat]

Corresponding author email: constanta [anonimizat]

Abstract

Because of the great taste attributes , aspect and specifically flavor , plus their importan ce in nutrition , peaches occupies an
important place in consumption in both, fresh and processed condition. Their superior dietary attributes are determined by
the content of vitamins , minerals , cellulose , acids and pectin. This paper aimed to present the impa ct of some produ ction
(fertiliser regime) and valorisation (preservin g conditions ) factors upon the quality and its maintainin g capacity durin g
nectarines preservin g. The organolepti c appre ciation , fruits’ firmness , biochemi cal compose , quantitative and qualitative
loses were determinated. The 'Southland ' cultivar (created in 1946, A merica), is very much appre ciated all over the world
for its great fruits (200-220g) and produ ctivity (30-35 kg/ tree). It was provided from the experimental plots of the Resear ch
Station for Fruit Growin g Constanta , fertili zed in different manner , with organic and chemi cal fertili zers, applied on soil
and/or foliar. The peaches were stored at RDIPMHP-B ucharest in three variants : in the ambient temperature (T=26-280C),
in cold conditions (T = 2-4°C) and cold + modified atmosphere conditions , durin g 7, 28 and 35 days, respe ctively. The best
results were obtained in case of the fertilisation with chemi cal fertilisers applied on soil + foliar , which induces the best
quality and maintainan ce durin g stored. The results also indicate the superiority of fruit stora ge in the modified atmosphere
comparin g with the others methods.

Key words: loses , quality , stora ge capacity, temperature

INTRODUCTION

The peaches are extremely perishable fruits,
which raises serious problems concerning the
maintaining of their quality during the
valorisation process, from the moment which
they are harvested until they reach the consumer
(Alexe et al., 2013).
The realisation and maintenance of fruit quality
depends on an ensemble of factors which
intervene in all the technological links related to
culture and valorisation, from the choosing of the
cultivar and the maintenance of the culture to
harvesting, conditioning and shipping. The peach tree cultivars display different characteristics as
concerns their storage and valorisation over a
longer period of time (Jamba and Carabulea,
2002). The storage capacity of peaches depends
on the quality of the raw material meant to be
stored, as well as on the conditions during
storage. The chemical composition of peaches,
which determines the level of biochemical
processes during storage and therefore, the
storage capacity is highly influenced by the
fertilisation regime. The dosage in which the
organic or mineral fertilisers is applied influences
the chemical composition of the fruit, having an
important effect upon the storage capacity
13Scientific Papers. Series B, Horticulture. V ol. LVIII, 2014
Print ISSN 2285-5653, CD-ROM ISSN 2285-5661, Online ISSN 2286-1580, ISSN-L 2285-5653

(Salunke, 1974 ; Ion, 2004).
Within valorisation technologies, it is
recommended that certain technological
processes regarding storage be applied, so that
they determine the inhibition of physiological
and biochemical processes within the fruit,
leading to the maintenance of their commercial
value for a period which as long as possible
(Burzo, 1986 ; Lill and King, 1999 ; Burzo et al.,
2005 ;).
The purpose of this paper is to evaluate the
obtaining and maintenance of fruit quality of the
peaches of the 'Southland' cultivar (American
cultivar, created in 1946, appreciated in all world
up to now for its great fruits and productivity),
according to the fertilising regime of the culture
and the storage conditions, after harvesting.

MATERIALS AND METHOD

The peaches were harvested from the
experimental plot of R.S.F.G. Constanta. The
'Southland' (Figure 1 and 2) is an semi-late
cultivar, the maturity period of fruits are in the
third decade of the July and first decade of
August. The fruit have a big weight (200-220 g)
and a spherical shape, flattened laterally and
ventral furrow is shallow.
The skin is thick, hairy and adherent to flesh,
color is yellow-orange, covered with red-purple
spots on the sunny side of fruit.

Figure 1. Branch with fruit of the Southland

The pulp is golden-yellow, with slight red
seepage around the kernel, with great taste and
flavor, relatively crisp, sweet-acidified,
succulent. The stone is medium size, ovoid, with inlay in the form of pockets and grooves, dark
brown and non adherent to the pulp. The tree is
auto-fertile, vigorous, with a very high yield
potential (30-35 kg/tree), is resistant to frost,
drought and disease, except Taphrina deformans.

Figure 2. Peaches of the Southland cultivar

Fruits are utilised for direct consumption and
processing. They present resistance to handling
and transport.
In ochard, the trees was conducted in 4 different
fertilisation variants:
– V1 – control (unfertilised)
– V2 – organic fertilisation (fermented manure)
– V3 – chemical fertilisation of the soil (NPK
complex fertilisers, in relation to 15:15:15.)
– V4 – chemical fertilisation of the soil + foliar
fertilisation (on soil with NPK complex fertilisers,
in relation to 15:15:15 and of the plant with the
foliar fertiliser Murtonik 20:20:20 +
microelements: Mn, Fe, Cu, Zn, Bo, chelation
form).
At the Research and Development Institute for
Processing and Marketing of the Horticultural
Products (RDIPMHP Bucharest), the fruits were
stored in three storage variants:
– ambient temperature (T = 26-28 °C, RH = 65-
70%), in 1kg packaging – warm ;
– refrigeration room (T = 2-4°C, RH = 83-87 %),
in packs of 1 kg covered with perforated
polyethylene film – cold storage ;
– refrigeration room (T = 2-4°C, RH = 92-96 %),
in 1 kg hermetic packages, so that the
composition of the atmosphere inside has
modified, by the reducing of the O2 content and
the increasing the CO 2 content and also of air
14

relative humidity-storage in modified atmosphere
– MA.
The storage duration (days) varied according to
the technological storage variant as follows:
– warm storage: 7
– cold storage: 28
– AM storage: 35
Immediately after harvesting, before the
beginning of the storage and at the end of this
period, certain determinations were carried out
concerning the fruits ’ firmness, as well as
organoleptic observations and biochemical
analyses of the main components (soluble dry
matter, soluble carbohydrates, titratable acidity).
In addition, losses were quantified, both the
quantitative (concerning the weight) and the
qualitative ones (by depreciation), losses which
occurred during the storage.
The firmness was determined by means of a OFD
weight penetrometer, which measures in
penetrometric units (1 PU = 0.1 mm) the depth to
which the conic needle is able to penetrate the
pulp of the fruit (length = 24 mm, diameter at its
basis = 4 mm). The measurements were
performed upon a number of 25 fruits /variant,
each fruit being penetrated in four points in the
equatorial area.
The appreciation of the organoleptic quality was
carried out by means of a sensorial testing of a
fruit, the evaluation method being a scale with
point from 1 to 100. Tasting sheet were used
which comprises three criteria: aspect, firmness,
taste. Each of these three criteria weighs
differently within the general grading, according
to their importance: the aspect represents 15%,
the firmness 35%, while the taste represents 50%.
Taking into account the total score, there are five
quality categories as follows:

Grade (quality category) Points
Very good 80-100
Good 60-79
Acceptable 40-59
Mediocre 20-39
Unsuitable 0-19
The methods used in order to determine the
biochemical components were:
– refractometry, using an ABBE refractometer, to
determine the soluble dry matter ; – the Bertrand titrimetric method to determine the
soluble carbohydrates ;
– the titrimetric method for the determination of
the titratable acidity.
Throughout the storage, the thermo-hydric
factors from the cold room were checked on a
daily basis, in order to ensure the fact that the
best conditions for maintaining the quality were
respected. At the same time, the capacity of the
maintain fruit quality was evaluated, including
the occurrence and development of different
storage diseases.

RESULTS AND DISCUSSIONS

a. Organoleptic quality
The results obtained following the organoleptical
testing (Figure 3) reveals the fact that at harvest,
the peaches obtained a high score (96.08 points),
because of their attractive aspect (12.75 points),
good firmness (35.00 points) and pleasant taste
(48.33 points).
Figure 3. Organoleptic appreciation of 'Southland' cultivar

The grade, according to the obtained points, was
“very good” for the fresh peaches – at harvest
(Table 1).

Table 1. The organoleptic appreciation of peaches at
harvest and after storage
Moment of determination Grade
At harvest very good
After warm storage very good
After cold storage very good
After AM storage very good

After 7 days of storage in an ambient
temperature, the organoleptic properties of the
peaches remained in good parameters (87.57
15

points) so that, although the score dropped a little
due to the diminishing of the firmness (31.49
points) and taste (41.33 points), the final grade
was also “very good”.
After cold storage for 28 days, the peaches of the
'Southland ' cultivar maintained their beautiful
aspect, good firmness and pleasant taste and,
following the organoleptic testing, obtained a
high score (93.35 points) and the grade “very
good”. After storage under conditions of
modified atmosphere for 37 days, the peaches
also maintained their firmness (35.00 points) and
pleasant taste (43.50 points), but increased their
beautiful aspect (43.50 points) and obtained the
grade “very good”, having a score of 93.35
points.
b. Firmness
At harvest time, the values of the firmness range
between 21.56 PU at the fruit from the V1
variant and 63.89 PU at the fruit from the V3
variant, the average per cultivar being of 40.08
PU (Table 2).
During warm storage, the peaches lose easy their
firmness, because of the quick ripening (175,08
PU). When the peaches are stored in cold
conditions, the intensity of the ripening process
diminishes, so that the fruit maintain their
structural and textural firmness for a longer
period of time (107,06 PU after 28 days of
storing).
By enriching the atmosphere in the storage space
with carbon dioxide, the metabolic processes
become even slower and the peaches maintain
their firmness (106,94 PU) for a longer period of
time (35 days).

Table 2. The firmness of peaches of the 'Southland ' cultivar
at harvest time and after storage period

c. Bioche mical composition
The content of 'Southland ' peaches, at harvest
time (initially), in main biochemical components,
is presented in Table 3. The results show that the
values of biochemical indicators from the fruits
vary according to variant of fertilization applied
to peach culture.
Analyzing the soluble dry matter content on
variants, it occurred that the V1 variant had the
lowest value of this indicator (10.64 %), and V4
variant had the highest value (11.18 %), closely
followed by V2 variant (11.14 %).
The soluble carbohydrate content presents the
highest value for the V2 variant (8.76 %) and
lowest in V1 variant (8.15 %).

Table 3. The main chemical components of 'Southland '
cultivar peaches at harvest time

In case of titratable acidity the differences
between the four variants are small, however the
V4 variant has the lowest content in malic acid
(0.76 %), and V1 variant, the highest content
(0.81 %).
The biochemical modifications occurred during
storage in the three variants are shown in Tables
4 to 6.
The high temperature during storage favors the
deployment with a great intensity of biochemical
processes in fruits, such as after 7 days of cold
storage the content in soluble dry matter
increased much, whereas the soluble sugars,
respectively malic acid fell much, compared with
the others storage methods (Table 4).

16

Table 4. The main chemical components of 'Southland'
cultivar after warm storage
Variant Solub.
dry
matter
(0R) Solub.
carbo –
hydrates
(%) Titratable
acidity
(malic acid/
100g)
V1 12.11 6.35 0.73
V2 12.09 7.17 0.64
V3 12.00 5.93 0.68
V4 12.09 7.12 0,63
Average 12.07 6.64 0.67

The lower temperature during cold storage leads
to the slow rhythm of these biochemical
processes, such as soluble dry matter increased
with 6.32% from the time of harvest and the
content in soluble carbohydrates and titratable
acids decreased with 2.13% , respectively 2.56%
(Table 5).

Table 5. The main chemical components of 'Southland'
cultivar after cold storage
Variant Solub.
dry
matter
(0R) Solub.
carbo –
hydrates
(%) Titratable
acidity
(malic acid/
100g)
V1 11.57 8.11 0.76
V2 11.80 8.51 0.76
V3 11.24 8.00 0.74
V4 11.81 8.43 0.76
Average 11.60 8.26 0.76

The cold effect is more pronounced during the
change of the gaseous composition of the air, by
increasing the concentration of the carbon
dioxide in storage space, such as during storage
in modified atmosphere, the soluble dry matter
content of the peaches has grown by only 1.55%
against initial moment, and titratable acidity
decreased with only 1.28% on the same time, as
evidenced in Table 6.
It was found that in case of storage in normal
temperature – warm (ambient temperature) for 7
days, total losses are higher in all 4 types of
fertilization, due to both mass (weight) losses,
but especially those by depreciation.

Table 6. The main chemical components of 'Southland'
cultivar after storage in M.A
Variant Solub.
dry
matter
(0R)Solub.
carbo –
hydrates
(%) Titratable
acidity
(malic acid/
100g)
V1 10.73 8.19 0.76
V2 11.36 8.51 0.78
V3 10.77 7.85 0.80
V4 11.46 8.39 0.76
Average 11.08 8,23 0.77

d. Qualitative and quantitative losses
The losses of the peaches recorded during the
storage are presented in Table 7.

Table 7. Losses recorded during the storage of peaches
under different technological conditions

At the V1 variant – control we recorded the
highest losses (43.11 %), and the V4 variant –
chemical fertilization in soil + foliar feeding, the
lowest (18.85 %). But skipping the variant of the
fertilization, the total losses recorded during the
warm peaches storage of the Southland are
29,39 % (10.97 % weight losses and 18.42 % by
depreciation losses).
The fruit impairment, in case of peaches, are
due to late infections caused by fungi Monilinia
laxa and M. fructigena before harvest, when they
are too little visible. After harvest, during
transport and storage, the attack rapidly evolves
(depending on temperature) and the entire fruit
rots. Moreover, during the storage can lead to the
rotting of the surrounding healthy fruit,
mycelium penetrating into them directly or
through injuries almost invisible.
The fruits can also be infected through wounds,
blows or pressure produced during harvest and
handling by the molds Rhizopus stolonifer and
Botrytis cinerea .
17

By using cold storage of peaches, losses were
recorded both quantitative (weight ) and
qualitative (depreciation ), much smaller than
warm keeping. Thus, the values found at the
'Southland ' cultivar, were : mass losses = 1.66%,
depreciation losses = 6.84% and total losses =
8.50%.
V4 variant is also remar kable, with 4.91% total
losses (1.61% mass losses + 3.30% qualitative
losses ), followed by V2 variant (losses : 6.65%,
1.45% and 5.20%, respectivel y). On last place,
with total losses of 15.05 % ranks V1 variant.
The losses determined after 35 days of storage in
modified atmosphere conditions were
significantl y lower values compared with the
others methods of storage.
The 'Southland ' cultivar recorded total losses of
2.91% (0.23% mass losses + 2.68% by
depreciation losses ) only. The V4 variant of
fertili zation was not reported losses of quality
and the quantitative losses were almost zero
(0.19%). A similar situation is found in the V2
variant too, with total losses of 0, 22%. Even in
the V1 variant the losses were significantl y
reduced, those being of 7.90%, 0.20% and
7.70% respectivel y.
From experimental data results that the
fertili zation variant of orchard peaches, the best
results in terms of losses during storage, from all
the three technological methods, is V4 variant,
followed by V2 variant, and the worst results
were obtained in V1 variant.

CONCLU SIONS

The peaches of the 'Southland ' cultivar are
appreciated from an organoleptic point of view,
given the fact that they obtained a fairly good
score upon their organoleptic testing at harvest.
The evolution of the quality during storage
depends on the conditions in the storage
environment and especiall y on the temperature
and gaseous composition.
From the point of view of the firmness, the best
results were obtained by the peaches which were
fertilised with foliar fertilisers. It was noticed that
the speed of metabolising pectin substances and
the decrease of the fruit’s firmness differs
according to the culture ’s fertilising regime but especiall y to the temperature and air composition
in the storage room.
Contents of peach fruit in main biochemical
indicators (soluble dry matter, soluble
carboh ydrate, organic acids ) varies depending on
crop fertili zation system. In terms of
biochemical, peaches from the culture fertili zed
with organic fertili zers and those from culture
fertili zed with chemical fertili zer incorporated
into soil and foliar fertili zation gave the best
results. The biodegradation of organic acids and
carboh ydrates is influenced by storage
temperature. As the storage temperature is
higher, the biodegradation is even more
pronounced. The chemical composition of the air
in storage space is also an important factor.
The abilit y to maintain the quality of peach fruit
varies also depending by the fertili zation system,
and storage conditions of the environment and
especiall y by temperature and gaseous air
composition. The V4 variant (chemical
fertili zation on soil + foliar feeding ) induces the
best storage capacit y, with the lowest quantitative
(weight ) and qualitative (depreciation ) losses.
The most efficient methods of fruits storage is
refrigeration room + modified atmosphere in
which were recorded the lowest losses during
storage.

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