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International Society for Tropical Root Crops (ISTRC) 7
The effect of process and environment on the nutritional value of
c
huño
Stef de Haan¹, Gabriela Burgos¹, Jesus Arcos², Raul Ccanto³, Maria Scurrah³, Elisa Salas¹ and Merideth
Bonierbale¹
¹ International Potato Center (CIP), Av. La Molina 1895, Lima, Peru, s.dehaan@cgiar.org
² Instituto Nacional de Innovación Agraria (INIA), Rinconada de Salcedo s/n, Puno, Peru
³ Grupo Yanapai, Jr. Atahualpa 297, Concepción, Perú
Abstract
The potato in its Andean center of origin is commonly freeze-dried to assure long-term storability and
consequent availability of food during periods of scarcity. The final product is known as
chuño
. Depending on
the process and cultivars used, different kinds of
chuño
are prepared: white
chuño
(
moraya
,
tunta
) and black
chuño
. This paper explores the nutritional value of
chuño
using data from research in the Peruvian Andes. The
paper specifically investigates the effect of regionally different processes on the mineral content of
chuño
: Zn,
Fe, Ca, K, P, Mg and Na. First, the effect of 4 processes (P), resulting in 2 types of white and black
chuño
respectively, for 4 cultivars (C) belonging to distinct botanical species (P*C interaction). Second, the influence of
locality, cultivar and process on nutrient concentrations (L*C*P interaction). Specifically, the effect of 3
contrasting growing environments on the mineral content of 4 cultivars processed into 2 types of white
chuño
.
Results of the first experiment show that the mineral content of
chuño
, independent of the mineral analyzed, is
significantly influenced by P*C interaction. Results of the second experiment show that particularly the dry
matter, Ca, Mg and Na content of white
chuño
is significantly affected by L*C*P interaction. The zinc, potassium,
phosphorus and magnesium content of all ‘types’ of
chuño
decreases in comparison with boiled (unprocessed)
tubers. White
chuño
generally contains stable to high iron and high calcium concentrations.
Keywords: potato, micro and macronutrient content, traditional freeze-drying.
Introduction
The cultivated potato in its Andean center of origin is commonly freeze-dried to assure long-term storability and
consequent availability of food during periods of scarcity. The final product is known as
chuño
(López Linage,
1991; Towle, 1961). Depending on the process followed and cultivars used, different kinds of
chuño
are
recognized (Condori Cruz, 1992). So-called black and white
chuño
are the result of different steps involved in the
processing pipeline. The elaboration of either ‘type’ takes advantage of severe frosts at night alternated with
high daytime levels of solar radiation and low levels of relative humidity during the months of June and July
(Woolfe, 1987). White
chuño
, also commonly known as
moraya
or
tunta
in the Quechua and Aymara languages
respectively (Gianella, 2004; Yamamoto, 1988), is frequently commercialized at markets while the use of black
chuño
is generally restricted to home consumption.
A main difference between the process of preparing black or white
chuño
relates to the prolonged exposure of
tubers to (running) water. White
chuño
is always washed or soaked, in part to remove glycolalkaloids. Black
chuño
, on the other hand, is not exposed to water and its elaboration is generally simpler, basically consisting of
tending, treading, freezing and drying (Mamani, 1981). The elaboration of white
chuño
has several regional
variants. It generally involves all of the following steps: tending, treading, freezing, washing and drying (Werge,
1979). Aside from the process of preparing chuño,
the particular potato cultivar involved influences the final
quality. Cultivars belonging to the bitter species
Solanum curtilobum
,
S. juzepczukii
and
S. ajanhuiri
are almost
exclusively used for traditional freeze-drying (Christiansen, 1977). Their high glycoalkaloid content restricts their
use for fresh consumption. Native-floury cultivars of non-bitter cultivated species and even improved cultivars
with
S. tuberosum
subsp.
tuberosum
within their pedigree are also commonly used to prepare
chuño
(De Haan
et al.
, 2009).
Woolfe (1987), quoting Collazos (1974), reports high energy contents for raw (non-boiled) white and black
chuño
of 323 and 333 kcal / 100 g on a fresh weight basis (FWB) compared to 80 kcal / 100 g for raw (non-boiled)
8 15th Triennial ISTRC Symposium
potatoes. De Haan
et al.
(2009) report slightly higher values in the case of boiled white
chuño
ranging from 390
to 394 kcal / 100 g on a dry weight basis (DWB). According to Christiansen (1978), between 67 to 83% and 18 to
30% of protein is lost during the elaboration of white and black
chuño
respectively. Other authors also report the
protein content of raw (non-boiled) black
chuño
to be higher compared to white
chuño
(Paredes and Gomez,
1987; Woolfe, 1987). Zavaleta
et al.
(1996) list the average energy, protein, iron and calcium content of 100 g of
raw (non-boiled) white
chuño
to be 323 kcal, 1.9 g, 3 mg and 92 mg and that of black
chuño
333 kcal, 4.0 g, 0.9
mg and 44 mg (FWB). These values are the same as those reported by Collazos (1974). Burgos
et al.
(2008) show
the protein, iron, zinc and calcium concentration of boiled white
chuño
of 9 native cultivars to range from 0.49 to
1.15 g, 0.29 to 0.65 mg, 0.04 to 0.14 mg and 18.9 to 31.0 mg respectively per 100 g (FWB). With the exception of
carbohydrate, calcium and iron, the nutrient content of white
chuño
is greatly reduced in comparison with fresh
potato (Woolfe, 1987). This is confirmed by recent research from Burgos
et al.
(2008) and De Haan
et al.
(2009)
which shows that the transformation of potato into white
chuño
does not significantly affect iron
concentrations, yet results in a decrease of the protein and zinc content, and an increase of calcium. Woolfe
(1987) points out that the nutrient content of black
chuño
is also reduced, but not to such a great extent as in
white
chuño
.
Highland farmers in central and southern Peru typically consume black and white
chuño
of diverse freeze-dried
potato cultivars rather than
chuño
from a single cultivar. However, little is known about the nutritional content
of diverse native cultivars (cultivars; C), the effect of regionally distinct ‘traditional’ processes (P), and the
influence of the environment (locality; L) on the macro- and micronutrient content of the black and white
chuño
variants. The research presented in this article explores the effect of 2 variants of both black and white
chuño
processing following standard ‘traditional’ procedures common to the departments of Huancavelica (central
Peru) and Puno (southern Peru) on the mineral content of 4 frequently used native potato cultivars grown in a
uniform growing environment. Additionally, it investigates the influence of 3 different growing environments
(localities; departments of Junín, Huancavelica and Puno) on the mineral content of 4 cultivars processed into 2
‘types’ of white
chuño
.
Materials and methods
Process by cultivar experiment (P*C)
Seed tubers of 4 cultivars were collected in Huancavelica and Puno. A native-floury and a native-bitter cultivar
were obtained from each department (table 1). Seed from the cultivars collected in Huancavelica were shipped
to Puno where a uniform trial site was located in the community of Salcedo at an altitude of 3,820 m. All cultivars
were planted on November the 12th 2007 in a field trial following a completely randomized block design (CRBD)
with 3 repetitions. Crop management was uniform and tubers were harvested on June the 5th 2008.
After harvest, fresh medium-sized and undamaged tubers from each locality, cultivar and repetition were
dispatched to the CIP’s nutrition laboratory for preparation and subsequent mineral analysis of unprocessed
tubers. Simultaneously, tubers of the same quality were sent to Huancavelica and Puno to process black and
white
chuño
following standard ‘traditional’ procedures. Processing of the 4 ‘types’ of
chuño
was done by
Andean farmers: black and white
chuño
of the ‘Huancavelica-type’, black and white
chuño
of the ‘Puno-type’.
Each of the different ‘types’ of
chuño
was processed at a different location and, depending on the specific steps
involved, took between 12 to 38 days to complete. Samples of all cultivars, repetitions and ‘types’ of
chuño
were
used for mineral analysis.
Table 1. Native potato cultivars cultivated in a field trial at a uniform location (Salcedo, Puno)
Cultivar Cultivar
category Species Ploidy Seed source
Azul Qanchillu
Bitter
S. juzepczukii
2
n
=3
x
=36 Huancavelica
Puqya
Floury
S. stenotomum
2
n
=2
x
=24 Huancavelica
Piñaza
Bitter
S. juzepczukii
2
n
=3
x
=36 Puno
Ccompis
Floury
S. tuberosum
subsp.
andigena
2
n
=4
x
=48 Puno
International Society for Tropical Root Crops (ISTRC) 9
Locality by cultivar by process experiment (L*C*P)
Seed tubers of 4 native-bitter cultivars were collected in Huancavelica and Puno (table 2). Seed of each cultivar
was shipped to locations in Junín, Huancavelica and Puno where field trials were installed following a completely
randomized block design (CRBD) with 3 to 4 repetitions (table 3). Crop management was uniform for each
locality with no agrochemicals applied and a single application of organic manure at 8 tons / ha.
After harvest, fresh medium-sized and undamaged tubers from each locality, cultivar and repetition were
dispatched to CIP’s nutrition laboratory for preparation and subsequent mineral analysis of unprocessed tubers.
Simultaneously, tubers of the same quality were sent to Huancavelica and Puno to process white
chuño
following standard ‘traditional’ procedures. Two ‘types’ of
chuño
were prepared by Andean farmers from both
departments: white
chuño
of the ‘Huancavelica-type’ and the ‘Puno-type’. Samples from all localities, cultivars,
repetitions and ‘types’ of
chuño
were used for mineral analysis.
Table 2. Native potato cultivars cultivated in a field trial at a single location (Salcedo, Puno)
Cultivar Cultivar
category Species Ploidy Seed source
Azul Qanchillu
Bitter
S. juzepczukii
2
n
=3
x
=36 Huancavelica
Suytu Siri
Bitter
S. curtilobum
2
n
=5
x
=60 Huancavelica
Locka
Bitter
S. juzepczukii
2
n
=3
x
=36 Puno
Piñaza
Bitter
S. juzepczukii
2
n
=3
x
=36 Puno
Table 3. Basis data for each of 3 different trial sites (localities; L)
Location Community District Province Altitude Planting Harvesting
Junín Quilcas Quilcas Huancayo 3,987 m 12-11-2007 10-06-2008
Huancavelica Dos de Mayo Yauli Huancavelica 4,357 m 29-10-2007 04-06-2008
Puno Salcedo Puno Puno 3,820 m 12-11-2007 05-06-2008
Preparation of analytical samples
Unprocessed tubers: a sample of 10 fresh tubers was prepared for each locality, cultivar and repetition. Tubers
were washed with tap water, rinsed with deionized, distilled water and subsequently boiled. The boiled tubers
were peeled and cut longitudinally into 4 sections (stem to bud end). Two opposite sections of each of the 10
tubers were combined to prepare each sample for mineral analysis. Two to 3 slices were taken from each section
to obtain a 50 g sample; these were placed in a glass petri dish and oven-dried for 24 hours at 80ºC. The dried
samples of approximately 12 to 16 g each were subsequently weighed and ground in an IKA A11 stainless steel
mill and stored at -20ºC in hermetically sealed plastic bags.
Processed tubers: a sample of 10 freeze-dried
tubers was prepared for each locality, cultivar, repetition and ‘type’
of
chuño
.
Chuño
tubers were washed, boiled, peeled and prepared to obtain samples for mineral analysis
applying the same procedures as detailed above for unprocessed tubers.
Mineral determination
Analytical sub-samples of 0.6 g each were taken after boiling from each of the repetitions of each cultivar and for
all treatments and digested at 140ºC in 70% (v/v) HNO3/HClO4. Samples were analyzed for iron (Fe), zinc (Zn),
calcium (Ca), potassium (K), phosphorus (P), magnesium (Mg), sodium (Na) and aluminum (Al) by inductively
coupled plasma-optical emission spectrophotometry (ICP-OES) using and ARL 3580 ICP. Aluminum (Al) was
included to provide an indication of possible iron contamination from soil particles (Darrell and Glanh, 1999).
Mineral determination was done on boiled samples because this is how potato tubers and traditionally freeze-
dried
chuño
are consumed and therefore the results are more appropriate for estimation of the contribution of
native potato cultivars and
chuño
to the human diet.
10 15th Triennial ISTRC Symposium
Statistical analysis
All the statistical tests were performed using SAS/STAT (version 8.2) software (SAS Institute 1999). Prior to the
analysis of variance (ANOVA), the data sets were tested for normality using the Kolmogorov-Smirnov test and as
not all the data were normally distributed, they were log10 transformed. When the combined ANOVA showed
significant differences for the interactions, simple effect analysis on the GLM procedure was conducted
considering the localities, cultivars and processes as fixed effects.
Results
The effect of process by cultivar
The mineral content of boiled
chuño
, independent of the mineral analyzed (Fe, Zn, Ca, K, P, Mg and Na), is
significantly influenced by the process (P), cultivar (C), and P*C interaction. Tables 4 and 5 show the general
results of the overall ANOVA for each of the 7 minerals analyzed. As an exception, only the dry matter content of
boiled
chuño
is not significantly influenced by the interaction between process and cultivar (P*C). Content
values for all cultivars and ‘types’ of
chuño
are shown in annex I. Findings described below are based on these
values.
Dry matter (DM). Independently of the cultivar employed, black
chuño
of the ‘Huancavelica-type’ retains
significantly higher levels of dry matter after boiling compared to the other ‘types’ of
chuño
. On average, the
cultivar
Azul Qanchillu
maintained a higher dry matter content compared to the other cultivars in boiled tubers,
both ‘types’ of boiled black
chuño
and boiled white
chuño
of the
‘Huancavelica-type’. To the contrary, the
cultivar
Piñaza
consistently had much lower dry matter contents compared to the other cultivars.
Iron (Fe). Only in the case of white
chuño
from Puno the influence of contamination was minimal (soil, dust).
Results for this particular ‘type’ of
chuño
show that its iron content is significantly influenced by the cultivar
employed. Interestingly, the iron content of boiled white
chuño
of the ‘Puno-type’ originating from native-bitter
cultivars was higher while that of native-floury cultivars was lower compared to content values of boiled tubers
of the same cultivars.
Zinc (Zn). Without exception, processing of
chuño
significantly reduces the tuber zinc concentration of all
cultivars analyzed with an average loss of 71.3% for white
chuño
of the ‘Huancavelica-type’, 65.7% for white
chuño
of the ‘Puno-type’, 49.6% for black
chuño
of the
‘Huancavelica-type’ and 51.0% for black
chuño
of the
‘Puno-type’. Results show that black
chuño
, independent of the specific ‘type’, retains higher levels of zinc
compared to white
chuño
. The cultivar
Puqya
contained the highest concentration of zinc in boiled tubers while
the cultivar
Piñaza
contained the highest concentration in boiled
chuño
for 3 out of 4 ‘types’ analyzed.
Calcium (Ca). Both ‘types’ of white
chuño
contained significantly higher concentrations of calcium compared to
boiled tubers while the content of both ‘types’ of black
chuño
generally tended to be lower. The only exception
to the latter is boiled black
chuño
of the ‘Huancavelica-type’ from the cultivar
Piñaza
. The average calcium
content of boiled white
chuño
of the ‘Huancavelica-type’ and the ‘Puno-type’ was 75.6% and 103.2% higher
compared to the concentration of boiled tubers. On the other hand, the average calcium content of boiled black
chuño
of the ‘Huancavelica-type’ and the ‘Puno-type’ was 16.5% and 35.0% lower compared to boiled tubers.
The cultivar
Piñaza
contained considerably higher levels of calcium in boiled tubers, both ‘types’ of white
chuño
and black
chuño
of the ‘Huancavelica-type’ compared to the other cultivars.
Potassium (K). The content of this mineral in boiled white and black
chuño
is affected negatively by freeze-
drying. Both ‘types’ of boiled black
chuño
show an average 2.6-fold decrease in their potassium concentration
compared to boiled tubers. White
chuño
is particularly subject to sizable losses with the ‘Huancavelica-type’ and
‘Puno-type’ respectively suffering an average 136-fold and 93-fold reduction of their potassium content
compared to potato tubers. The potassium content of both ‘types’ of boiled white
chuño
is not significantly
influenced by the cultivar used while its concentration in boiled tubers and both ‘types’ of black
chuño
is
significantly dependent on the cultivar.
Phosphorus (P). The phosphorus content of all ‘types’ of
chuño
is reduced significantly by traditional freeze-
drying. The average phosphorus concentration of boiled black
chuño
as compared to boiled potato tubers
reduced 45.2% and 45.8% for the ‘Huancavelica-type’ and ‘Puno-type’ respectively. Losses for both ‘types’ of
International Society for Tropical Root Crops (ISTRC) 11
white
chuño
, the ‘Huancavelica-type’ and ‘Puno-type’ respectively, average 67.8% and 62.7%. Differences in the
phosphorus content of the different cultivars were significant for boiled tubers and both ‘types’ of black
chuño
while differences in the content of the distinct cultivars was insignificant for both ‘types’ of white
chuño
.
Magnesium (Mg). Without exceptions, the magnesium concentration of all ‘types’ of boiled
chuño
was
significantly lower compared to the content of boiled potato tubers. On average losses were higher for both
‘types’ of white
chuño
, 67.6% for white
chuño
of the ‘Huancavelica-type’ and 72.3% for white
chuño
of the
‘Puno-type’, compared to both ‘types’ of black
chuño
: 53.2% for black
chuño
of the ‘Huancavelica-type’ and
56.5% for black
chuño
of the ‘Puno-type’. The cultivar
Piñaza
retained the highest concentration in
(unprocessed) tubers, both ‘types’ of black
chuño
and white
chuño
of the ‘Puno-type’ when compared to the
other cultivars while the cultivar
Azul Qanchillu
maintained the highest content in black
chuño
of the
‘Huancavelica-type’. Both native-floury cultivars show higher average losses of magnesium compared to both
native-bitter cultivars.
Sodium (Na). Both ‘types’ of black
chuño
show a decrease of sodium concentrations for all of the cultivars
analyzed. Depending on the specific cultivar, levels of decrease range from 4.9 to 45.8% for black
chuño
of the
‘Huancavelica-type’ and 5.3 to 31.8% for black
chuño
of the ‘Puno-type’. With the exception of the cultivar
Ccompis
, the sodium content of boiled white
chuño
of the ‘Huancavelica-type’ was 18.7 to 88.0% lower
compared to the content of boiled tubers. Interestingly, the sodium content of boiled white
chuño
of the ‘Puno-
type’ was significantly higher compared to the content of boiled tubers. Depending on the cultivar, the average
sodium content of white
chuño
of the ‘Puno-type’ increases by 53.7 to 811.4%. No significant differences
between cultivars were encountered concerning the sodium concentration of white
chuño
of the ‘Huancavelica-
type’ and black
chuño
of the ‘Puno-type’. However, the sodium content of boiled tubers, black
chuño
of the
‘Huancavelica-type’ and white
chuño
of the ‘Puno-type’ depended significantly on the specific cultivar
employed.
12 15th Triennial ISTRC Symposium
Table 4. Analysis of variance for the dry matter, iron, zinc and calcium content of boiled
chuño
Dry Matter (%) Fe (mg / kg)ª §, DWB Zn (mg / kg)ª, DWB Ca (mg / kg), DWB
Source DF Mean
Square F-value Pr > F Mean
Square F-value Pr > F Mean
Square F-value Pr > F Mean
Square F-value Pr > F
Repetition (proc) 10 6,932 1,830 0,006 1,400 0,002 0,940 1709,013 0,380
Cultivar (C) 3 133,961 35,350 ** 0,120 26,700 ** 0,071 31,590 ** 516688,064 114,020 **
Process (P) 4 126,482 33,370 ** 0,171 37,990 ** 0,538 238,320 ** 658781,303 145,380 **
Process*Cultivar 12 5,527 1,460 0,017 3,830 ** 0,018 7,930 ** 50374,516 11,120 **
Error 30 3,790 0,004 4531,569
Corrected total 59 1157,156
Mean 30,402 27,260 5,924 473,014
CV 6,403 4,767 6,608 14,231
R² 0,902 0,907 0,975 0,972
ª = data transformed to log10; ** p>0,01; § = values likely influenced by contamination
Table 5. Analysis of variance for the potassium, phosphorus, magnesium and sodium content of boiled
chuño
K (mg / kg), DWB P (mg / kg), DWB Mg (mg / kg)ª, DWB Na (mg / kg), DWB
Source DF Mean
Square F-value Pr
> F
Mean
Square F-value Pr >
F
Mean
Square F-value Pr >
F
Mean
Square F-value Pr >
F
Repetition (proc) 10 338333,000 0,660 10310,000 0,430 0,001 0,540 177,948 0,420
Cultivar (C) 3 4104863,000 7,990 ** 822215,560 34,550 ** 0,177 97,060 ** 6185,000 14,530 **
Process (P) 4 431689321,000 840,150 ** 5568310,830 234,000 ** 0,575 316,070 ** 33408,032 78,460 **
Process*Cultivar 12 3071236,000 5,980 ** 167541,940 7,040 ** 0,015 7,990 ** 1909,905 4,490 **
Error 30 513826,000 23796,670 0,002 425,778
Corrected total 59
Mean 5441,186 1386,333 417,594 51,702
CV 13,174 11,127 1,667 39,910
R² 0,991 0,974 0,982 0,933
ª = data transformed to log10; ** p>0,01
International Society for Tropical Root Crops (ISTRC) 13
The effect of locality by cultivar by process
The overall ANOVA indicates that the dry matter, Fe, Ca, Mg and Na content of boiled white
chuño
is significantly
dependent on the locality (L), cultivar (C), process (P), and L*C*P interaction effect (tables 6 and 7). However, iron
content levels, particularly of white
chuño
of the ‘Huancavelica-type’, were influenced by contamination. The Zn
content of boiled white
chuño
is significantly influenced by the locality (L), cultivar (C), process (P) and L*P
interaction while the K content is significantly influenced by the locality (L), process (P) and L*P interaction. Both
Zn and K are not significantly dependent on L*C or L*C*P interaction effects. The P content of boiled white
chuño
is significantly influenced by the locality (L), cultivar (C), process (P), L*C and L*P interaction, but not by
the L*C*P interaction effect. Annex II shows the dry matter, Fe, Ca, Mg and Na content values for all localities,
cultivars and ‘types’ of
chuño
. In the case of Zn, K and P the same annex shows average content values by
locality (L) and process (P), but not by cultivar (C), as no significant L*C*P interaction effects were found.
Findings described below are based on results shown in annex II.
Dry matter (DM). Without exception the dry matter content of boiled (unprocessed) tubers and both ‘types’ of
white
chuño
of all cultivars is significantly influenced by the locality where the potato has been grown.
Interestingly, for all localities and cultivars, the dry matter content of white
chuño
of the ‘Huancavelica-type’ was
always higher while that of white
chuño
of the ‘Puno-type’ was always lower compared to content values of
boiled (unprocessed) tubers. The average dry matter content of boiled (unprocessed) tubers and both ‘types’ of
white
chuño
from tubers grown in Huancavelica was always lower compared to materials from the other
localities. The only exception to the former concerns white
chuño
of the ‘Puno-type’ from the cultivar
Azul
Qanchillu
. The dry matter content of
chuño
from all localities and cultivars, with the exception the cultivar
Locka
produced in Puno and Junín, was significantly influenced by the process.
Iron (Fe). High aluminum concentrations indicate likely soil contamination of white
chuño
of the ‘Huancavelica-
type’. Therefore only the results concerning iron content values for boiled (unprocessed) tubers and white
chuño
of the ‘Puno-type’ are considered for detailed interpretation. Results for unprocessed tubers and white
chuño
of
the ‘Puno-type’ indicate that the influence of the locality on iron content values is non-significant for both
processes and all cultivars with the single exception of boiled (unprocessed) tubers from the cultivar
Suytu Siri
.
Depending on the locality and cultivar, average iron concentrations of white
chuño
of the ‘Puno-type’ were
between 11.2 to 45.6% higher compared to boiled (unprocessed) tubers.
Zinc (Zn). The average zinc content of boiled (unprocessed) tubers and white
chuño
of both the ‘Huancavelica-
type’ and ‘Puno-type’ is significantly influenced by the locality where the potato has been produced (L*P
interaction effect). The zinc content of white
chuño
is not significantly influenced by L*C or L*C*P interaction
effects. The zinc content of both ‘types’ of white
chuño
is always significantly lower compared to boiled tubers.
Depending on the locality, average losses fluctuated between 70.0 to 80.5% for white
chuño
of the
‘Huancavelica-type’ and 48.3 to 81.5% for white
chuño
of the ‘Puno-type’.
Calcium (Ca). Without exception the calcium content of boiled (unprocessed) tubers and both ‘types’ of white
chuño
of all cultivars is significantly influenced by the locality where the potato has been grown. The calcium
concentration of both types of white
chuño
, independent of the locality and cultivar, was always higher
compared to boiled (unprocessed) tubers. In the case of white
chuño
of the ‘Huancavelica-type’ 1.7 to 5.6-fold
and in the case of white
chuño
of the ‘Puno-type’ 2.1 to 8.1-fold higher. Independently of the cultivar employed,
the calcium concentration of both types of
chuño
processed from tubers produced in Huancavelica always
tended to be considerably higher compared to the same
chuño
elaborated from tubers produced in Puno or
Junín. The calcium content of
chuño
from all localities and cultivars was also significantly influenced by the
process.
Potassium (K). The potassium content of boiled (unprocessed) tubers is significantly influenced by the locality
where potatoes have been produced (L*P interaction effect). Yet, no significant effect of locality on the
potassium concentration of both ‘types’ of white
chuño
was found. The potassium content of white
chuño
is not
significantly influenced by L*C, C*P or L*C*P interaction effects. The potassium content of both ‘types’ of white
chuño
was always significantly lower compared to boiled tubers. Average losses above 99% of the original
content are normal.
Phosphorus (P). The phosphorus content of boiled (unprocessed) tubers and white
chuño
of the ‘Huancavelica-
type’ is significantly influenced by the locality where potatoes have been produced (L*P interaction effect). No
significant effect of locality on the phosphorus concentration of white
chuño
of the ‘Puno-type’ was found. The
phosphorus content of white
chuño
is also significantly influenced by L*C and C*P interaction effects. The
phosphorus content of both ‘types’ of white
chuño
was always significantly lower compared to boiled tubers.
14 15th Triennial ISTRC Symposium
Depending on the locality, average losses fluctuated between 62.3 to 73.0% for white
chuño
of the
‘Huancavelica-type’ and 61.2 to 71.4% for white
chuño
of the ‘Puno-type’.
Magnesium (Mg). Without exception the magnesium concentration of boiled (unprocessed) tubers and white
chuño
of the ‘Huancavelica-type’ of all cultivars is significantly influenced by the locality where the potato has
been grown. With the exception of the cultivar
Piñaza
, the magnesium concentration of white
chuño
of the
‘Puno-type’ was generally not significantly influenced by locality. The magnesium concentration of both ‘types’
of
chuño
was always significantly lower compared to boiled tubers. Depending on the locality and cultivar,
average losses fluctuated between 69.7 to 81.9% for white
chuño
of the ‘Huancavelica-type’ and 62.0 to 89.7%
for white
chuño
of the ‘Puno-type’.
Sodium (Na). The sodium content of boiled (unprocessed) tubers of all cultivars is significantly influenced by the
locality where the potato has been grown. The content of both ‘types’ of white
chuño
, on the other hand, is not
significantly influenced by the locality. Indepent of the cultivar, both ‘types’ of
chuño
elaborated with tubers
from the locality Huancavelica increased its sodium content compared to boiled tubers. White
chuño
of the
‘Huancavelica-type’ elaborated from tubers produced in Puno and Junín generally had lower sodium
concentrations compared to content values of boiled tubers. To the contrary, white
chuño
of the ‘Puno-type’
elaborated from tubers produced in Puno and Junín generally had higher sodium concentrations compared to
content values of boiled tubers.
International Society for Tropical Root Crops (ISTRC) 15
Table 6. Analysis of variance for the dry matter, iron, zinc and calcium content of boiled white
chuño
Dry Matter (%) Fe (mg / kg)ª §, DWB Zn (mg / kg), DWB Ca (mg / kg), DWB
Source DF Mean
Square F-value Pr > F Mean
Square F-value Pr > F Mean
Square F-value Pr > F Mean
Square F-value Pr > F
Locality (L) 2 305,24 72,51 ** 0,24 29,89 ** 126,14 402,31 ** 2229788,71 72,78 **
Repetition (Loc.) 8 4,24 2,39 * 0,01 0,76 0,30 0,20 30882,78 3,76 **
Cultivar (C) 3 29,91 16,86 ** 0,07 6,72 ** 12,66 8,25 ** 52286,49 6,37 **
Locality*Cultivar 6 10,74 6,05 ** 0,02 1,99 2,28 1,49 20988,01 2,56 *
Process (P) 2 372,54 209,96 ** 1,50 140,77 ** 2064,51 1345,99 ** 7172493,15 874,13 **
Locality*Process 4 17,48 9,85 ** 0,00 0,16 137,98 89,96 ** 156551,50 19,08 **
Cultivar*Process 6 41,89 23,61 ** 0,01 0,63 2,38 1,55 33953,48 4,14 **
L*C*P 12 13,45 7,58 ** 0,03 2,58 ** 2,32 1,51 20545,42 2,50 **
Error 80 1,77 0,01 1,53 8205,25
Corrected total 123
Mean 26,90 31,35 8,86 811,88
CV 4,95 7,18 13,97 11,16
R² 0,94 0,84 0,98 0,97
ª = data transformed to log10; ** p>0.01; * p>0.05; § = values likely influenced by contamination
Table 7. Analysis of variance for the potassium, phosphorus, magnesium and sodium content of boiled white
chuño
K (mg / kg), DWB P (mg / kg), DWB Mg (mg / kg), DWB Na (mg / kg), DWB
Source DF Mean
Square F-value Pr
> F
Mean
Square F-value Pr
> F
Mean
Square F-value Pr >
F
Mean
Square F-value Pr >
F
Locality (L) 2 75184365,00 195,77 ** 4263259,30 35,18 ** 549813,04 417,82 ** 3,62 94,86 **
Repetition (Loc.) 8 382292,00 0,70 122161,40 3,93 ** 1302,08 0,50 0,04 0,65
Cultivar (C) 3 807321,00 1,48 212787,00 6,85 ** 36373,09 14,04 ** 0,18 3,02 *
Locality*Cultivar 6 507969,00 0,93 86016,90 2,77 * 2557,91 0,99 0,15 2,51 *
Process (P) 2 4772247574,00 8732,49 ** 59663754,60 1921,50 ** 9966966,67 3847,63 ** 12,20 207,57 **
Locality*Process 4 83968718,00 153,65 ** 2542023,30 81,87 ** 323775,76 124,99 ** 2,49 42,31 **
Cultivar*Process 6 681194,00 1,25 30123,50 0,97 11968,91 4,62 ** 0,13 2,18
L*C*P 12 549756,00 1,01 41521,30 1,34 4867,04 1,88 * 0,11 1,92 *
Error 80 546494,00 31050,60 2590,42
Corrected total 123
Mean 6835,89 1680,24 650,89 60,59
CV 10,81 10,49 7,82 10,04
R² 1,00 0,98 0,99 0,91
ª = data transformed to log10; ** p>0.01; * p>0.05
16 15th Triennial ISTRC Symposium
Conclusions
Process by cultivar
The zinc, potassium, phosphorus and magnesium contents of all ‘types’ of boiled
chuño
are low in comparison
with those of boiled (unprocessed) tubers. The process of traditional freeze-drying, without exception,
negatively affects the nutritional value of
chuño
for these 4 minerals. In addition, the content of these minerals is
reduced more drastically in both ‘types’ of white
chuño
as compared to both ‘types’ of black
chuño
. It seems
likely that the higher loss of these minerals in white compared to black
chuño
originates from the exposure of
tubers to (running) water during the process of freeze-drying.
The influence of the 4 different regional variants of freeze-drying on the dry matter, iron, calcium and sodium
content of
chuño
was not as linear as for the minerals discussed above. Differences in the dry matter content of
boiled tubers versus
chuño
were fairly modest for all ‘types’ of
chuño
, except black
chuño
of the ‘Huancavelica-
type’ which had a considerably higher dry matter content compared to boiled tubers. Iron content values for
white
chuño
of the ‘Puno-type’ clearly indicate a strong influence of the cultivar. The calcium concentration of
boiled
chuño
is strongly influenced by the actual process of freeze-drying. Both ‘types’ of white
chuño
contained
significantly higher concentrations of calcium compared to boiled (unprocessed) tubers. Both ‘types’ of black
chuño
, on the other hand, on average contained lower concentrations of calcium compared to boiled tubers.
The fact that the calcium content of white
chuño
is nearly double compared to (unprocessed) potato tubers and
black
chuño
suggests that that this particular mineral might be absorbed from the water. A similar phenomenon
may be occurring in the case of sodium as average concentrations of this mineral in white
chuño
of the ‘Puno-
type’ were generally much higher compared to those of boiled tubers. Sodium concentrations in all other ‘types’
of
chuño
tended to be significantly lower compared to content values of boiled tubers.
Locality by cultivar by process
Independent of the locality where potatoes are produced, the zinc, potassium, phosphorus and magnesium
concentrations of
chuño
always decrease in comparison with mineral content values of boiled tubers of the
same treatment. The dry matter, calcium, magnesium and sodium content of boiled white
chuño
is significantly
dependent on the L*C*P interaction effect. Without exception the dry matter and calcium content of boiled
(unprocessed) tubers and both ‘types’ of white
chuño
of all cultivars is significantly influenced by the locality
where the potato has been grown. Results confirm that the calcium content of white
chuño
from all localities
and cultivars increases considerably in comparison with concentrations in boiled tubers.
The magnesium concentration of boiled (unprocessed) tubers and white
chuño
of the ‘Huancavelica-type’ of all
cultivars is significantly influenced by the locality where the potato has been produced while it’s content in
white
chuño
of the ‘Puno-type’ is generally not significantly affected by locality. The sodium content of boiled
(unprocessed) tubers of all cultivars is, whereas content vales of both ‘types’ of
chuño
are not, significantly
influenced by the locality. Results confirm that the sodium content of white
chuño
of the ‘Puno-type’ is always
higher in comparison with concentrations in boiled tubers. Content levels of sodium in white
chuño
of the
‘Huancavelica-type’ may either increase or decrease in comparison with boiled (unprocessed) tubers, depending
on the locality where the potato was produced.
The concentrations of some minerals is significantly influenced by the locality, but not by L*C*P interaction
effects. Such is the case for zinc and phosphorus. The zinc content of boiled (unprocessed) tubers and white
chuño
of both the ‘Huancavelica-type’ and ‘Puno-type’ is significantly influenced by the locality where the
potato has been produced. Further, the phosphorus content of boiled (unprocessed) tubers and white
chuño
of
the ‘Huancavelica-type’ is significantly influenced by locality whereas concentrations in white
chuño
of the
‘Puno-type’ are not significant affected.
The locality of potato production has little influence on the iron and potassium content of white
chuño
. Results
for white
chuño
of the ‘Puno-type’ indicate that the influence of the locality on iron content values is non-
significant. Average iron concentrations of white
chuño
of the ‘Puno-type’ were always higher compared to
boiled (unprocessed) tubers. While the potassium content of boiled (unprocessed) tubers is significantly
influenced by the locality where potatoes have been produced, the same is not true for potassium
concentrations of both ‘types’ of white
chuño
. The main cause is the enormous reduction of potassium caused
by traditional freeze-drying, amounting to losses above 99% of the original content.
International Society for Tropical Root Crops (ISTRC) 17
Chuño and human nutrition
In general terms, both white and black
chuño
are relatively poor sources of macro- and micronutrients.
Interventions aimed at combating child malnutrition in the Andean highlands will probably have the highest
possible impact when levels of consumption of meat, milk products, fruit and (leafy) vegetables can be
increased. Nevertheless, these products are generally scarce in Andean communities located above 3.500 m of
altitude. Potato, consumed as boiled tubers or
chuño
and often combined with grains such as barley, makes up
the bulk of daily food intake. In an environment where harvests and food storage occur once a year, and where
risks of crop failure and consequent temporal food shortages caused by frost, hail or drought are frequent, the
preparation of
chuño
does contribute significantly to local food security.
Chuño
, just as other traditionally
freeze-dried products (e.g.
kaya
), allow Andean households to overcome periods of relative food shortage.
Additionally, the consumption of
chuño
is imbedded in the Andean culture and cuisine. From a human nutrition
perspective the benefits of
chuño
consumption, beyond its long-term storability and year-round availability as
an energy-rich food source, include the stable to high iron and high calcium content of white
chuño
as
compared to unprocessed potato tubers and the comparatively high levels of retention of zinc, potassium,
phosphorus and magnesium in black compared to white
chuño
. Additionally, the commercial value of high-
quality white
chuño
may allow rural families to enrich their diets with foods obtained through monetary
purchase.
Literature cited
Burgos, G., De Haan, S., Salas, E. and Bonierbale, M. 2008. Protein, iron, zinc and calcium concentrations of potato
following traditional processing as “chuño”. Journal of Food Composition and Analysis:
doi:10.1016/j.jfca.2008.09.001.
Christiansen, J. 1977. The utilization of bitter potatoes to improve food production in the high altitude of the
tropics. PhD thesis. Cornell University, Ithaca.
Christiansen, J. 1978. Las papas amargas: fuente de proteínas y calorías en los Andes. pp. 201-203. In: UNSCH
(ed.), Anales del Primer Congreso Internacional de Cultivos Andinos. Universidad Nacional de San Cristóbal
de Huamanga (UNSCH), Inter-American Institute for Cooperation on Agriculture (IICA), Ayacucho.
Collazos, C. 1974. La Composición de los Alimentos Peruanos. Ministerio de Salud, Lima.
Condori Cruz, D. 1992. Tecnología del chuño. Boletín del IDEA 42(2):70-97.
Darrell, R. and Glanh, R. 1999. Micronutrient bioavailability techniques: accuracy, problems and limitations. Field
Crop Research 60:93-113.
De Haan, S., Burgos, G., Liria, R., Bonierbale, M. and Thiele, G. 2009. The role of biodiverse potatoes in the human
diet in central Peru: nutritional composition, dietary intake and cultural connotations. pp. 161-182. In: S. de
Haan, Potato Diversity at Height: multiple dimensions of farmer-driven
in-situ
conservation in the Andes. PhD
thesis. Wageningen University, Wageningen.
Gianella, T. 2004. Chuño blanco, ‘tunta’ o ‘moraya’: un proceso natural de conservación. LEISA Revista de
Agroecología 20(3):29-31.
López Linage, J. (ed.) 1991. De Papa a Batata: la difusión española del tubérculo andino. Ministerio de
Agricultura, Pesca y Alimentación, Madrid.
Mamani, M. 1981. El Chuño: preparación, uso, almacenamiento. pp. 235-246. In: H. Lechtmand and A.M. Soldi
(eds.), La Tecnología en El Mundo Andino: runakunap kawsayninkupaq rurasqankunaqa (Tomo 1).
Universidad Nacional Autónoma de México (UNAM), México.
Paredes, S. and Gomez, O. 1987. Elaboración del chuño negro y blanco a partir de papa amarga, var. ‘Ruckii’ y var.
‘Q’etta’. pp. 358-362. In: UNAP (ed.), Procedimientos del V Congreso Internacional de Sistemas Agropecuarios
Andinos. Universidad Nacional del Altiplano (UNAP), Corporación Departamental de Desarrollo de Puno
(CORDEPUNO) Instituto Nacional de Investigación y Promoción Agropecuaria (INIPA), Puno.
Towle, M.A. 1961. The Ethnobotany of Pre-Columbian Peru. Viking Fund Publications in Anthropology, Chicago.
Werge, R.W. 1979. Potato processing in the central highlands of Peru. Ecology of Food and Nutrition 7:229-234
Woolfe, J.A. 1987. The Potato in the Human Diet. Cambridge University Press, Cambridge.
18 15th Triennial ISTRC Symposium
Yamamoto, N. 1988. Potato Processing: learning from a traditional Andean system. pp. 160-172. In: CIP (ed.), The
Social Sciences at CIP: social science planning conference, Lima, Peru (7-10 September 1987). International
Potato Center (CIP), Lima.
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Ministerio de Salud (MINSA), Instituto Nacional de Salud (INS), Lima.
International Society for Tropical Root Crops (ISTRC) 19
Annex 1. Dry matter and mineral content values
(process by cultivar experiment; P*C)
Dry matter content (%) of boiled potato tubers and four ‘types’ of boiled
chuño
Potato tubers
White
chuño
‘Hvca-type’
Black
chuño
‘Hvca-type’
White
chuño
‘Puno-type’
Black
chuño
‘Puno-type’
Av. SD (±) Av. SD (±) Av. SD (±) Av. SD (±) Av. SD (±)
Qanchillu
33.4 1.3 32.7 3.4 39.8 6.9 28.8 0.7 32.7 1.1
Ccompis
29.0 1.0 32.0 1.1 37.6 1.1 29.8 1.5 29.0 1.8
Piñaza
24.3 1.8 27.7 1.9 31.0 1.9 22.3 1.8 26.7 2.0
Puqya
30.6 0.1 30.4 0.6 34.2 0.7 26.4 0.6 29.8 0.9
Iron content (mg/kg; DWB¹) of boiled potato tubers and four ‘types’ of boiled
chuño
Potato tubers
White
chuño
‘Hvca-type’ª
Black
chuño
‘Hvca-type’ª
White
chuño
‘Puno-type’
Black
chuño
‘Puno-type’ª
Av. SD
(±)
Av. SD
(±)
Av. SD
(±)
Av. SD
(±)
Av. SD
(±)
P x G
effect
sliced
by G
Qanchillu
21.9 2.8 62.1 15.8 38.1 6.4 25.0 0.7 31.0 1.7 **
Ccompis
17.3 0.6 21.9 3.0 27.0 2.9 13.7 2.2 23.2 1.9 **
Piñaza
18.6 2.8 32.4 12.0 28.2 2.3 24.0 3.7 27.6 4.6 **
Puqya
21.5 2.9 41.1 10.6 27.3 4.5 15.7 1.6 27.3 3.9 **
P x G effect
sliced by P
ns ** * ** ns
¹ = Dry Weight Basis; ª = values likely influenced by contamination; P = process; C = cultivar; ** p>0.01; * p>0.05
Zinc content (mg/kg; DWB¹) of boiled potato tubers and four ‘types’ of boiled
chuño
Potato tubers
White
chuño
‘Hvca-type’
Black
chuño
‘Hvca-type’
White
chuño
‘Puno-type’
Black
chuño
‘Puno-type’
Av. SD
(±)
Av. SD
(±)
Av. SD
(±)
Av. SD
(±)
Av. SD
(±)
P x G
effect
sliced
by G
Qanchillu
10.2 0.6 3.7 0.5 5.8 0.5 3.4 0.4 5.4 0.5 **
Ccompis
10.6 0.5 3.0 0.4 4.8 0.3 2.9 0.2 4.2 0.1 **
Piñaza
11.3 0.7 3.4 0.8 6.5 0.4 5.7 0.8 8.4 0.4 **
Puqya
13.4 2.4 2.7 0.3 5.6 0.4 3.5 0.3 3.9 0.4 **
P x G effect
sliced by P
* ** * ** **
¹ = Dry Weight Basis; P = process; C = cultivar; ** p>0.01; * p>0.05
Calcium content (mg/kg; DWB¹) of boiled potato tubers and four ‘types’ of boiled
chuño
Potato tubers
White
chuño
‘Hvca-type’
Black
chuño
‘Hvca-type’
White
chuño
‘Puno-type’
Black
chuño
‘Puno-type’
Av. SD
(±)
Av. SD
(±)
Av. SD
(±)
Av. SD
(±)
Av. SD
(±)
P x G
effect
sliced
by G
Qanchillu
383.3 46.2 703.3 20.8 356.7 63.5 870.0 78.1 293.3 11.5 **
Ccompis
270.0 10.0 490.0 60.8 199.0 28.1 463.3 25.2 191.4 25.2 **
Piñaza
523.3 119.3 1030.0 26.5 533.3 37.9 1236.7 98.1 253.3 41.6 **
Puqya
303.3 5.8 426.7 75.7 198.7 2.3 540.0 155.9 194.5 4.5 **
P x G effect
sliced by P
** ** ** ** ns
¹ = Dry Weight Basis; P = process; C = cultivar; ** p>0.01; * p>0.05
20 15th Triennial ISTRC Symposium
Potassium content (mg/kg; DWB¹) of boiled potato tubers and four ‘types’ of boiled
chuño
Potato tubers
White
chuño
‘Hvca-type’
Black
chuño
‘Hvca-type’
White
chuño
‘Puno-type’
Black
chuño
‘Puno-type’
Av. SD (±) Av. SD
(±)
Av. SD
(±)
Av. SD
(±)
Av. SD
(±)
P x G
effect
sliced
by G
Qanchillu
14000.0 1417.7 146.6 22.8 7233.3 472.6 98.1 13.3 6266.7 57.7 **
Ccompis
14133.3 1159.0 165.4 100.4 5366.7 251.7 530.0 10.0 5033.3 152.8 **
Piñaza
15766.7 1361.4 70.5 21.3 5966.7 208.2 119.7 30.4 8766.7 808.3 **
Puqya
15366.7 1222.0 109.9 53.4 5066.7 873.7 216.9 24.8 4400.0 953.9 **
P x G effect
sliced by P
** ns ** ns **
¹ = Dry Weight Basis; P = process; C = cultivar; ** p>0.01; * p>0.05
Phosphorus content (mg/kg; DWB¹) of boiled potato tubers and four ‘types’ of boiled
chuño
Potato tubers
White
chuño
‘Hvca-type’
Black
chuño
‘Hvca-type’
White
chuño
‘Puno-type’
Black
chuño
‘Puno-type’
Av. SD (±) Av. SD
(±)
Av. SD
(±)
Av. SD
(±)
Av. SD
(±)
P x G
effect
sliced
by G
Qanchillu
2866.7 321.5 810.0 45.8 1600.0 60.0 850.0 17.3 1463.3 72.3 **
Ccompis
1986.7 196.3 893.3 104.1 1263.3 97.1 956.7 41.6 1153.3 125.8 **
Piñaza
3033.3 208.2 750.0 17.3 1543.3 100.2 1023.3 15.3 1860.0 87.2 **
Puqya
2150.0 229.1 666.7 96.1 1050.0 130.0 810.0 190.8 996.7 202.6 **
P x G eff.
sliced by P
** ns ** ns **
¹ = Dry Weight Basis; P = process; C = cultivar; ** p>0.01; * p>0.05
Magnesium content (mg/kg; DWB¹) of boiled potato tubers and four ‘types’ of boiled
chuño
Potato tubers
White
chuño
‘Hvca-type’
Black
chuño
‘Hvca-type’
White
chuño
‘Puno-type’
Black
chuño
‘Puno-type’
Av. SD (±) Av. SD
(±)
Av. SD
(±)
Av. SD
(±)
Av. SD
(±)
P x G
effect
sliced
by G
Qanchillu
863.3 60.3 316.7 5.8 443.3 11.5 213.3 23.1 380.0 17.3 **
Ccompis
706.7 60.3 256.7 20.8 290.0 10.0 183.5 10.2 253.3 15.3 **
Piñaza
916.7 104.1 306.7 30.6 526.7 15.3 340.0 26.5 600.0 20.0 **
Puqya
826.7 83.3 191.9 25.1 310.0 10.0 189.8 43.9 236.7 32.1 **
P x G eff.
sliced by P
* ** ** ** **
¹ = Dry Weight Basis; P = process; C = cultivar; ** p>0.01; * p>0.05
Sodium content (mg/kg; DWB¹) of boiled potato tubers and four ‘types’ of boiled
chuño
Potato tubers
White
chuño
‘Hvca-type’
Black
chuño
‘Hvca-type’
White
chuño
‘Puno-type’
Black
chuño
‘Puno-type’
Av. SD (±) Av. SD
(±)
Av. SD
(±)
Av. SD
(±)
Av. SD
(±)
P x G
effect
sliced
by G
Qanchillu
43.2 26.5 20.2 1.7 41.0 26.1 118.8 20.2 31.8 11.5 **
Ccompis
16.2 13.5 18.8 2.1 13.6 12.5 147.9 12.9 12.6 7.7 **
Piñaza
123.8 55.2 14.9 2.0 67.1 27.6 190.3 19.5 5.3 2.5 **
Puqya
17.2 14.6 14.0 1.6 13.7 9.9 113.5 15.4 10.3 6.1 **
P x G eff.
sliced by P
** ns ** ** ns
¹ = Dry Weight Basis; P = process; C = cultivar; ** p>0.01; * p>0.05
International Society for Tropical Root Crops (ISTRC) 21
Annex 2. Dry matter and mineral content values
(locality by cultivar by process experiment; L*C*P)
Dry matter content (%) of boiled potato tubers and two ‘types’ of boiled
chuño
(locality x cultivar x
process)
Potato tubers
White
chuño
‘Hvca-type’
White
chuño
‘Puno-type’
Locality Cultivar
Av. SD (±) Av. SD (±) Av. SD (±)
L*C*P effect sl.
by L*C
Huancavelica
Azul Qanchillu
25.92 1.44 26.19 1.07 22.72 0.57 **
Puno
Azul Qanchillu
33.36 1.33 34.36 2.29 19.21 0.91 **
Junin
Azul Qanchillu
29.39 0.81 34.60 2.38 26.22 0.74 **
L*C*P effect sliced by C*P ** ** **
Huancavelica
Locka
24.43 1.23 25.42 1.61 21.80 0.83 **
Puno
Locka
26.87 1.53 27.35 1.42 25.50 0.54 ns
Junin
Locka
27.60 0.52 28.03 0.48 25.54 0.82 ns
L*C*P effect sliced by C*P ** * **
Huancavelica
Piñaza
22.03 0.67 27.19 1.40 21.12 0.80 **
Puno
Piñaza
24.27 1.79 32.04 1.24 23.62 0.96 **
Junin
Piñaza
25.59 1.64 35.24 2.32 24.11 0.44 **
L*C*P effect sliced by C*P ** ** *
Huancavelica
Suytu Siri
23.09 1.21 24.26 1.49 20.26 0.68 **
Puno
Suytu Siri
28.27 1.28 31.45 2.07 27.49 0.83 **
Junin
Suytu Siri
28.82 1.00 34.31 3.16 26.68 0.84 **
L*C*P effect sliced by C*P ** ** **
L = locality; P = process; C = cultivar; ** p>0.01; * p>0.05
Iron content (mg/kg; DWB¹) of boiled potato tubers and two ‘types’ of boiled
chuño
(locality x cultivar
x process)
Potato tubers
White
chuño
‘Hvca-type’ª
White
chuño
‘Puno-type’
Locality Cultivar
Av. SD (±) Av. SD (±) Av. SD (±)
L*C*P effect sl.
by L*C
Huancavelica
Azul Qanchillu
28.19 3.02 80.94 34.38 35.22 1.11 **
Puno
Azul Qanchillu
21.94 2.85 45.56 15.96 31.94 4.27 **
Junin
Azul Qanchillu
18.92 2.69 35.62 8.20 24.97 2.42 **
L*C*P effect sliced by C*P ns ** ns
Huancavelica
Locka
20.03 2.84 34.91 3.40 25.82 1.34 **
Puno
Locka
18.09 1.98 38.29 12.98 25.90 1.63 **
Junin
Locka
14.85 0.97 48.76 20.35 17.93 0.74 **
L*C*P effect sliced by C*P ns ns ns
Huancavelica
Piñaza
22.00 1.06 79.95 38.64 24.46 0.91 **
Puno
Piñaza
18.64 2.75 44.50 12.29 25.01 0.42 **
Junin
Piñaza
16.08 0.92 32.97 13.04 19.39 0.26 **
L*C*P effect sliced by C*P ns ** ns
Huancavelica
Suytu Siri
22.44 1.77 37.94 7.64 26.81 2.19 **
Puno
Suytu Siri
19.14 0.47 64.18 18.24 21.95 1.26 **
Junin
Suytu Siri
14.19 1.95 38.62 15.49 17.41 0.57 **
L*C*P effect sliced by C*P * ** ns
¹ = Dry Weight Basis; ª = values likely influenced by soil contamination; L = locality; P = process; C = cultivar; ** p>0.01; * p>0.05
22 15th Triennial ISTRC Symposium
Zinc content (mg/kg; DWB¹) of boiled potato tubers and two ‘types’ of boiled
chuño
(locality x
process)
Potato tubers
White
chuño
‘Hvca-type’
White
chuño
‘Puno-type’
Locality
Av. SD (±) Av. SD (±) Av. SD (±)
L*P effect sl.
by L
Huancavelica 21.05 2.24 4.11 1.24 3.89 0.76 **
Puno 10.40 0.95 3.12 0.66 5.38 1.60 **
Junin 18.11 1.94 4.82 0.89 4.68 0.82 **
L*P effect sl. by P ** ** *
Calcium content (mg/kg; DWB¹) of boiled potato tubers and two ‘types’ of boiled
chuño
(locality x
cultivar x process)
Potato tubers
White
chuño
‘Hvca-type’
White
chuño
‘Puno-type’
Locality Cultivar
Av. SD (±) Av. SD (±) Av. SD (±)
L*C*P effect sl.
by L*C
Huancavelica
Azul Qanchillu
427.50 56.79 1255.00 165.83 1446.67 64.29 **
Puno
Azul Qanchillu
383.33 46.19 773.33 55.08 1226.67 49.33 **
Junín
Azul Qanchillu
155.34 22.93 700.00 91.29 790.00 26.46 **
L*C*P effect sliced by C*P ** ** **
Huancavelica
Locka
485.00 57.45 1392.50 84.61 1480.00 62.45 **
Puno
Locka
543.33 70.24 1143.33 90.74 1123.33 58.59 **
Junín
Locka
220.34 62.56 700.00 42.43 920.00 69.28 **
L*C*P effect sliced by C*P ** ** **
Huancavelica
Piñaza
432.50 130.74 1095.00 203.06 1436.67 15.28 **
Puno
Piñaza
523.33 119.30 913.33 75.72 1146.67 61.10 **
Junín
Piñaza
129.53 48.45 652.50 136.72 1010.00 85.44 **
L*C*P effect sliced by C*P ** ** **
Huancavelica
Suytu Siri
457.50 179.14 1277.50 219.15 1656.67 159.48 **
Puno
Suytu Siri
460.00 98.49 813.33 111.50 1173.33 64.29 **
Junín
Suytu Siri
123.13 50.23 690.00 34.64 1003.33 51.32 **
L*C*P effect sliced by C*P ** ** **
L = locality; P = process; C = cultivar; ** p>0.01; * p>0.05
Potassium content (mg/kg; DWB¹) of boiled potato tubers and two ‘types’ of boiled
chuño
(locality x
process)
Potato tubers
White
chuño
‘Hvca-type’
White
chuño
‘Puno-type’
Locality
Av. SD (±) Av. SD (±) Av. SD (±)
L*P effect sl. by L
Huancavelica 23062.50 1388.94 90.97 58.38 69.70 22.46 **
Puno 14500.00 1231.41 96.50 45.91 113.04 43.90 **
Junin 18500.00 1067.08 152.24 69.49 117.33 33.14 **
L*P effect sl. by P ** ns ns
Phosphorus content (mg/kg; DWB¹) of boiled potato tubers and two ‘types’ of boiled
chuño
(locality x
process)
Potato tubers
White
chuño
‘Hvca-type’
White
chuño
‘Puno-type’
Locality
Av. SD (±) Av. SD (±) Av. SD (±)
L*P effect sl. by L
Huancavelica 3862.50 452.95 1066.25 56.08 1105.00 65.30 **
Puno 2858.33 264.43 772.50 38.41 957.50 114.58 **
Junin 2291.88 276.63 865.00 75.10 888.33 88.51 **
L*P effect sl. by P ** ** ns
International Society for Tropical Root Crops (ISTRC) 23
Magnesium content (mg/kg; DWB¹) of boiled potato tubers and two ‘types’ of boiled
chuño
(locality x
cultivar x process)
Potato tubers
White
chuño
‘Hvca-type’
White
chuño
‘Puno-type’
Locality Cultivar
Av. SD (±) Av. SD (±) Av. SD (±)
L*C*P effect sl.
by L*C
Huancavelica
Azul Qanchillu
1360.00 65.83 407.50 34.03 263.33 15.28 **
Puno
Azul Qanchillu
863.33 60.28 300.00 10.00 256.67 25.17 **
Junín
Azul Qanchillu
1247.50 86.17 420.00 25.82 293.33 30.55 **
L*C*P effect sliced by C*P ** ** ns
Huancavelica
Locka
1450.00 102.31 370.00 34.64 270.00 43.59 **
Puno
Locka
856.67 56.86 263.33 15.28 293.33 15.28 **
Junín
Locka
1292.50 20.62 420.00 21.60 310.00 26.46 **
L*C*P effect sliced by C*P ** ** ns
Huancavelica
Piñaza
1587.50 53.15 430.00 58.31 293.33 66.58 **
Puno
Piñaza
916.67 104.08 286.67 20.82 400.00 17.32 **
Junín
Piñaza
1305.00 79.37 450.00 35.59 320.00 17.32 **
L*C*P effect sliced by C*P ** ** *
Huancavelica
Suytu Siri
1357.50 60.76 417.50 65.00 270.00 26.46 **
Puno
Suytu Siri
800.00 26.46 293.33 28.87 216.67 5.77 **
Junín
Suytu Siri
1180.00 14.14 425.00 36.97 310.00 65.57 **
L*C*P effect sliced by C*P ** ** ns
L = locality; P = process; C = cultivar; ** p>0.01; * p>0.05
Sodium content (mg/kg; DWB¹) of boiled potato tubers and two ‘types’ of boiled
chuño
(locality x
cultivar x process)
Potato tubers
White
chuño
‘Hvca-type’
White
chuño
‘Puno-type’
Locality Cultivar
Av. SD (±) Av. SD (±) Av. SD (±)
L*C*P effect sl.
by L*C
Huancavelica
Azul Qanchillu
0.93 0.77 15.56 2.44 86.38 3.95 **
Puno
Azul Qanchillu
43.15 26.48 16.23 1.16 163.77 20.24 **
Junín
Azul Qanchillu
17.38 6.57 17.85 2.57 146.96 4.13 **
L*C*P effect sliced by C*P ** ns ns
Huancavelica
Locka
2.19 2.48 10.73 0.48 112.32 3.38 **
Puno
Locka
196.54 78.38 13.87 1.32 159.51 8.11 **
Junín
Locka
31.53 31.60 15.81 1.89 141.38 12.87 **
L*C*P effect sliced by C*P ** ns ns
Huancavelica
Piñaza
6.24 3.78 15.52 3.74 129.78 9.12 **
Puno
Piñaza
123.80 55.19 13.48 0.40 199.23 17.99 **
Junín
Piñaza
21.13 18.15 19.73 1.90 176.20 16.52 **
L*C*P effect sliced by C*P ** ns ns
Huancavelica
Suytu Siri
4.25 2.86 13.70 2.54 120.07 11.80 **
Puno
Suytu Siri
35.37 13.58 13.54 1.72 131.08 7.55 **
Junín
Suytu Siri
22.85 21.74 17.64 2.82 171.11 50.65 **
L*C*P effect sliced by C*P ** ns ns
L = locality; P = process; C = cultivar; ** p>0.01; * p>0.05
