growing season also can alter the degree of savoying of a ... Pub. 316, 1938). Canned vegetables served in in ... blanched 4 minutes at SO'C, filled into. 303x406 cans ... difference between leaf types in ob- pearance the savoy cultivar was not.
For Processing - Savoy or Smooth Leaf Spinach? By S.J. KAYS and J.W. WILLIAMS
fvHILE a wide variety of spinach cultivars are grown, all fall into one of three classes—savoy, semi-savoy, and smooth—based on leaf morphology.
The savoy types have an irregular or
"crumpl^" surface which results
from the continued growth of the parenchyma cells between the veins of
the leaf. Temperature during the
growing season also can alter the
degree of savoying of a specific cultivar, with cool temperatures, especially at night, increasing the character (R. Magruder et al, USDA Misc. Pub. 316, 1938). Canned vegetables served in in
members for color, leaf integrity, and Since differences in quality of the general appearance. Color also was commercial samples reflect difanalyzed using a Gardner Color Dif- ferences in field production, ference Meter standardized against a processing, and cultivar, the two light green plate (L = 52.0, a =-3.3, b = cultivars in the experimental lots 30.9). Resistance to shear was grown and processed under identical
measured on a TldOg sample using a conditions were analyzed. These data FTC Model TP-lA shear-press fitted (Table 1) support the findings with Mdth a 300 lb load cell. commercial samples, in that leaf inQuality analysis of commercially tegrity and shear values were lower in packed spinach samples showed little the savoy type, and in general apdifference between leaf types in ob- pearance the savoy cultivar was not jective measures of product color considered superior to the smooth-leaf (Table 1). However, differences were type. found between individual cultivars Length of holding at 82 °C did not
with regard to -a and b values. appreciably affect product color
stitutions and restaurants often must
In addition, subjective evaluation by (Table 2). Also, leaf integrity, general
be kept heated for long times. This is believed to result in a general decline,
a sensory panel showed no consistent appearance, and shear values did not differences between the smooth and significantly decline with holding for savoy types with regard to color after up to 6 hours. While this test did not heating. Smooth-leaf samples were simulate the mechanical agitation that rated higher in general appearance might be encountered in a serving line,
with time, in nutritional and esthetic
quality of the product.
Because of this decline, savoy-type cultivars of spinach have been preferred over smooth-leaf types by some processors, who feel that they maintain leaf integrity better under these conditions. That conclusion is
supported by little analytical evidence, but it has a pronounced effect on the
and leaf integrity by sensory results do indicate that samples held evaluation, and their shear values were for a period of time such as might be
higher than savoy-leaf type samples. encountered in a cafeteria in general
Part of the difference in shear values not decline in parameters of visual between the two types may reflect the quality. effect of longer petioles, characteristic This very limited study cannot he of a number of the smooth-leaf considered to have established the
economics of production and
cultivars. However, one smooth-leaf superiority of one leaf type over the
processing in many areas, since savoy types typically yield less than smooth-
sample that did not have extended other for canning spinach, hut it does petioles also had higher value than point toward the need for a more e i t h e r s a v o y c u l t i v a r. d e t a i l e d s t u d y.
part, results in a differential in raw
Table 1. Gardner Color, Panel Rating, and Shear Values for 5 Commercial and 2 Experimental Lots of Spinach Representing Two Leaf Types
leaf t)^. This yield difference, in product prices of as much as $27 to $31 per metric ton between regions. Therefore,
we
undertook
this
preliminary inquiry into the validity of some assumptions supporting the use of one leaf type over another in canned spinach. Five lots of commercially canned
Panel rating' Gardner color' Leaf Color
S h e a r, lb/200g
9.5ab
21.7a
1.2cd
7.1b
7.3c
7.1t>c
82.7d
S m o o t h
22.9a
I.Oab
10.1c
6.6a
7.0bc
6.7ab
81.3d
S m o o t h
21.5a
l . i b c
9.1a
7.8c
7.2c
7.4c
72.3c
Savoy
21.6a
1.3d
9.3ab
7.3b
6.3a
6.6a
62.3b
22.5a
0.9a
9.7bc
7.1b
6.4b
6.7ab
47.9a
22.0
1.1
9 . 6
7.2
7.2
7.1
78.8
22.1
1.1
9.5
7.2
6.4
6.7
55.1
Smooth (Norgreen)
22.7a
0.7a
9.9a
7.3a
6.8a
6.5a
72.3b
Savoy (Hybrid 612)
22.7a
0.8a
10.2a
& 5 a
6.5a
6.4a
41.7a
Smooth
comparison of product quality.
mean
Savoy mean
Experimental samples
petiole, smooth-leaf ty^; and 2 shortNorgreen and the semi-savoy type Hybrid 612. The experimental lots were blanched 4 minutes at SO'C, filled into 303x406 cans, and processed at 122*'C
b
a
S m o o t h
Savoy
Experiment Station, were selected for
petiole, savoy types. Experimental lots consisted of the smooth-leaf type
-
Commercial samples
whole leaf spinach, and other samples grown and processed at the Main Commercial lots consisted of 2 longpetiole, smooth-leaf types; 1 short-
General
tegrity appearance
Leaf In L
type
'Mean separation of commercial or experimental samples in columns by Duncan's multiple range test at 5% level; sam ples followed by Mte same letter do not differ.
Table 2. Effect of Maintaining Canned Commercial Samples of Smooth-leaf and Savoy Spinach at 82°C for Various Lengths of Time on Gardner Color, Panel Rating, and Shear Press Values
for 49 minutes in a still-type retort. Commercial samples were removed from cans and heated at 100"C for 10
minutes and then held for 0, 2, 4, or 6
Panel rating' Gardner color'
Ti m e , hours
L
- a
b
Color
hours at 82''C. Experimental samples were analyzed after heating for 10 minutes at 100 "C.
Samples were rated by a panel of 12
Leaf in
General
Shear,
tegrity
appearance
lb/200g
0
21.0
1.1
9.5
7.1
6.8
6.9
71.3
2
22.1
1.1
9.5
7.3
7.0
7.2
70.8
4
22.2
1 . 1
9 . 6
7.0
6.6
6.6
67.9
6
22.0
1.1
9.6
7.2
6.9
6.9
67.2
D r. K a y s w a s a s s o c i a t e t i o r t i c u l t u r a l f o o d s c i e n t i s t ;
'There were no significant differences among any means at the 5 percent level, according to Duncan's multiple range
M r. W i l l i a m s I s r e s e a r c h a s s i s t a n t .
test.
September-October, 1977
15