**1. Introduction**

Acorn squash are an old cultivar-group of *Cucurbita pepo* L. subsp. *texana* (Scheele) Filov [1]. The fruits have a distinctive turbinate shape with several longitudinal ridges and furrows [2], and they are rather small, weighing 300–1500 g. Most acorn squash cultivars have a dark green rind with a deep-orange flesh and sugar content of 12%–18% [3]. The fruit is an excellent source of nutrients and vitamins and can be stored for about 2 months at temperatures not lower than 10 ◦C without developing chilling injury and losing its dark color, which is a good indicator for freshness and marketing [4]. Under the hot Israeli climate, the fruits lose their dark-green rind color, become dull orange or yellow within a short time after harvest, and thereby lose value. Because of its dark green color and distinctive taste after cooking, this fruit is called Dela'at Armonim (chestnut pumpkin) in Hebrew [3].

A technology of cleaning and disinfecting fresh-harvested produce in hot water (45–62 ◦C) over brushes for a very short time (15–25 s) is used commercially in Israel [5]. This technology is applied to several fruits and vegetables to reduce decay development and maintain fresh produce quality through prolonged storage and shelf life.

Very little information is available about the storage life of sweet acorn squash. Therefore, the goal of this research was to determine the best storage temperature for acorn squash fruits and to evaluate the use of hot water rinsing and brushing technology to clean and disinfect the fruits before prolonged storage for 3.5 months.

#### **2. Materials and Methods**

#### *2.1. Plant Materials*

Acorn squash fruits (*Cucurbita pepo* L. cv. Or) (Origene Seeds, Ltd., Giv'aat Brener, Israel), uniform in color and size with no defects, were harvested with a clipper from a commercial field in the central region of Israel. They were selected according to commercial maturity indexes (initial color ~125 Hue◦; unit weight about 600–700 g).

#### *2.2. Experiments and Treatments*

In a marketing simulation in 2016 dry-brushed fruits were kept at 10, 15 or 20 ◦C, and 95, 95 or 70% RH, respectively for 2.5 month, followed by 3 days at 20 ◦C. In 2017, in light of preliminary results, the fruits were subjected to hot water rinsing and brushing (HWRB) treatment at 54 ± 1 ◦C for 15 s as described by Fallik [6] and kept at 15 or 20 ◦C for 3.5 months, and then for 3 days at 20 ◦C. Untreated fruits and those treated by tap water rinsing and brushing (TWRB) served as controls.

## *2.3. Quality Evaluation*

Fruit quality was evaluated after 3.5 months at 15 or 20 ◦C followed by 3 days at 20 ◦C as follows: Weight loss percentage was calculated from the weights of 10 fruits before and after storage. Total soluble solids (TSS) contents were measured in 10 fruits by removing and squeezing a segmen<sup>t</sup> of flesh (from the peel to the seedbed) onto a digital refractometer (Atago, Tokyo, Japan); the same 10 fruits were tested for color, firmness and weight loss, Fruit epidermal color was evaluated with a Minolta Chroma Meter (Minolta, Ramsey, NJ, USA) that was calibrated against a white standard tile; two sides of each of 10 fruits were measured near the equator, and the results expressed as Hue angle (h◦). Firmness was measured in newtons (N) (C-peak mode) with a motorized Chatillon penetrometer equipped with a 6-mm conic plunger (John Chatillon & Sons, New Gardens, NY, USA); each measurement was applied on opposite sides of each of 10 fruits, near the equator. Decay was expressed as the percentage of fruits with visible fungal mycelia on the peel.

## *2.4. Statistical Analysis*

Three experiments/harvests were conducted each year. Each treatment consisted of 2 cartons, each consisted 14–15 fruits per carton (28–30 fruits per treatment), two repetitions per treatment. All data were subjected to one- or two-way statistical analysis at *P* = 0.05 with the JMP-11 Statistical Analysis Software Program (SAS Institute, Cary, NC, USA).
